when an object falls freely , the distance covered by the object is
a. directly proportional to time
b. directly prop. to square time
c. inversely prop. to time
d.direcly prop. to double time

Answer:

According to Newton’s first law of motion, a force must act on it to move an object at rest.

Explanation:

According to the Newton's first law of motion, for an object to change its velocity (either a change in the magnitude or the direction), there must be a cause to it which is defined as a net external force.

So for an object to move from rest, an external force must be applied to it.

Final answer:

According to Newton's first law of motion, to move an object at rest, a net external force must be applied. This law, also known as the law of inertia, indicates that an object will not change its state of motion without the influence of an external force. This demonstrates the connection between motion and forces.

Explanation:

According to Newton’s first law of motion, for an object at rest to move, it must be acted upon by a net external force. This law, also known as the law of inertia, explains that without such a force, an object will remain in its current state, whether that is at rest or in motion at a constant velocity. The crucial point is that any change in motion - initiating movement from rest, altering speed, or changing direction - requires the influence of a net external force. This force could be anything from a push or pull, to gravity or friction acting on the object.

The common observation that objects naturally tend to slow down and come to a halt is not due to inertia but rather the result of frictional or other forces acting against the object’s motion. Therefore, to move an object at rest, a force must be applied that is greater than the resisting forces, such as friction. This illustrates the fundamental nature of motion and forces as described by Newton’s first law.

participating only in cardiovascular exercises

Participating only in cardiovascular exercises is not a recommended change in physical activity for aging individuals.

This is the type of physical activity which stresses the cardiorespiratory system.

It is however not ideal for aging individuals due to their weak body system which is why option D was chosen.

Read more about Cardiovascular exercise here https://brainly.com/question/11860586

#SPJ2

The Benefit of Fossil Fuel Consumption among the Given Options is :

B. Cheap Energy

Because :

✿  Fossil Fuels are Non - Renewable.

✿  They result in High Pollution and Greenhouse Gases.

A benefit of fossil fuel consumption is B. Cheap energy.

Fossil fuels, such as coal and natural gas, are widely available and can generate electricity at a relatively low cost. Despite their environmental drawbacks, including high carbon emissions and pollution, the existing infrastructure and technological development around fossil fuels make them an inexpensive energy source.

Given that ;

Energy (work ) Produced by bulb =20 KJ = 20000 J

Input power = 15 KW

Output power given by the bulb  = Rate of doing work

                                                   = Work ÷ time

                                                   = 20000 ÷ 1800   (since 1 min = 60 seconds)

                                                   = 11.11 W

Noe, efficiency is the ratio of output power to input power

                                                   η = output power ÷ input power

                                                      = 11.11 ÷ 15

                                                      = 0.74

                                                      = 74%

Efficiency of light bulb is 74%

If you liked the procedure, please give me brainliest

Some places where you can find smooth muscles in your body are,

the walls of your blood vessels,

the walls of your stomach,

the intestines,

and the iris of your eye.

those are just some.

if you need different ones, I have more.

Answer:

3.7 km/h

Explanation:

Let's call v the proper speed of the boat and v' the speed of the water in the river.

When the boat travels in the direction of the current, the speed of the boat is:

v + v'

And it covers 50 km in 3 h, so we can write

[tex]v+v' = \frac{50 km}{3 h}=16.7 km/h[/tex] (1)

When the boat travels in the opposite direction, the speed of the boat is

v - v'

And it covers 50 km in 5.4 h, so

[tex]v-v'=\frac{50 km}{5.4 h}=9.3 km/h[/tex] (2)

So we have a system of two equations: by solving them simultaneously, we find the value of v and v':

[tex]v+v'=16.7 \\v-v'=9.3[/tex]

Subtracting the second equation from the first one we get:

[tex](v+v')-(v-v')=16.7-9.3\\2v'=7.4\\v'=3.7[/tex]

So, the speed of the water is 3.7 km/h.

Convection occurs because the oceanic waters heat up becoming less dense. This water moves above the cooler water, and give off its heat to the surrounding environment. As it cools, it begins to sink, and the process begins again.

The correct answer is Option B.

Explanation: When a fluid is heated unevenly, it starts moving in convection cells, carrying thermal energy from its warmer parts to its colder parts. Such motion due to temperature differences is called a convection current. Ocean currents may be considered convection currents because warm water rises and cold water moves in to replace it. Warm currents carry thermal energy from warmer regions near the equator toward the poles. Cold currents move toward the equator, making the temperature there lower than it would be otherwise.

Given data:

M.A. =  8 (No units),

Ramp height (h)= 1.5 m, lifted,

Determine how long is the ramp=?

General formula

Mechanical Advantage = (Ramp length) ÷ (Ramp height),

                             M.A = l  ÷ h

                                  8 × 1.5 = l = 12 m long

length of the ramp l ramp = 12 m

The length of the ramp can be found using the mechanical advantage formula. Given a mechanical advantage of 8 and a height of [tex]1.5 m[/tex], the ramp length is [tex]12 m[/tex].

Determining the Length of the Ramp

To determine the length of the ramp, we can use the formula for mechanical advantage (MA) of an inclined plane, which is given by:

MA = Length of ramp / Height of ramp

From the question, we know the mechanical advantage (MA) is 8, and the height of the ramp is 1.5 meters. Let's use the formula to find the length of the ramp:

[tex]8 = \text{Length of ramp} / 1.5[/tex]

[tex]\text{Length of ramp} = 8 \times 1.5 = 12 m[/tex]

Therefore, the ramp is 12 meters long.

(50 meters) / (3 seconds) = (50/3) (meters/sec) = (16 and 2/3) meters/sec .

Speed is correct.

It's NOT velocity.

They're different things.

Answer:

Shine lasers of various colors at a narrow slit in an index card and measure the distance between the bright spots.

Explanation:

When the light passes through the narrow opening or the obstacles, it bends. This process is called the diffraction of light. The experiment to investigate the wavelength on the diffraction pattern is " to find the wavelength of laser light with the help of diffraction process ".

In this experiment, a laser light, a slit and the detector is placed on the optical bench. Then the laser light is passes on the slit and diffraction pattern can be seen in the screen.

So, the correct option that shows the best experiment to investigate the wavelength on the diffraction pattern is " Shine lasers of various colors at a narrow slit in an index card and measure the distance between the bright spots ".

(6) first choice: the frequency appears higher and wavelength is shorter.

The car approaches a stationary observer and so the sound will appear to have shorter wavelength. This creates an effect of its siren to sound with higher frequency than it would do if both were stationary.

(7) The Doppler formula for frequency in the case of a stationary observer and source approaching it is as follows:

[tex]f_O = \frac{v}{v-v_s}\cdot f= \frac{343\frac{m}{s}}{(343-25)\frac{m}{s}}\cdot 400Hz \approx 431Hz[/tex]

The wavelength is then

[tex]\lambda = \frac{343\frac{m}{s}}{431Hz}\approx 0.80 m[/tex]

The third choice "0.80m; 431Hz" is correct

Dave's ball, with a mass of 0.07 kg thrown at 28 m/s, reaches a maximum height of approximately 40 meters. This is calculated using the conservation of energy principle, equating the initial kinetic energy to the potential energy at the ball's highest point.

To determine how high the ball goes when Dave throws it straight up into the air, we can use the principles of physics and the conservation of energy. Given that the ball has a mass of 0.07 kg and is thrown at a speed of 28 m/s, we ignore the air resistance as per the question's instruction. The maximum height (h) reached by the ball can be calculated using the equation derived from conservation of mechanical energy: the kinetic energy at the point of release equals the potential energy at the highest point.

The kinetic energy (KE) when the ball is thrown is KE = (1/2)mv^2, where m is the mass and v is the initial velocity. The potential energy (PE) at the highest point is PE = mgh, where g is the acceleration due to gravity (approximately 9.81 m/s^2) and h is the height. When the ball reaches its highest point, its velocity is 0 m/s, so its kinetic energy is also 0, and all the initial kinetic energy has been transferred to potential energy. Therefore, (1/2)mv^2 = mgh.

Solving for h gives us h = (1/2) * (v^2 / g). Plugging in the values, we get h = (1/2) * (28^2 / 9.81) which equals to approximately 40 meters. So, the ball thrown by Dave reaches a height of roughly 40 meters.

Answer: Simple machine

When volcanoes erupt, they emit a mixture of gases and particles into the air. Some of them, such as ash and sulphur dioxide, have a cooling effect, because they (or the substances they cause) reflect sunlight away from the earth. Others, such as CO2, cause warming by adding to the the greenhouse effect.

Volcanoes can have long-term effects on the climate, making the world cooler.

Hope this helps☺

F=m*a=>a=F/m=10000/1267=7.89 m/s²

d=v₀t+a't²/2<=>394.6=112.5*a'=>a'=3.5

a-a'=7.89-3.5=4.39 m/s²

This difference causes friction forces

We apply the second principle of dynamics: vector: F + N + G + Ff = ma (vector vectors, I can not here)

Scalar: Ox: F-Ff = ma

            Oy N-mg = 0

Ff = -ma+ F =-1267*7.89+10000=-8869+10000=1131 N

This frictional force (Ff) is opposite to the traction (F)

Answer:

speed of truck (v) =  22 m/s ,

angle of hill (Θ) =15°

Find

Vertical component (Fv) = ?

Harizontal component (Fh) =?

               Vertical component (Fh) = V cosΘ

                                                        = 22. cos 15

                                                        = 21.25 m/s.

               Harizontal component (Fv) = V sinΘ

                                                            = 22. sin 15

                                                            = 5.69 m/s.

a. The horizontal component of the truck's velocity is 5.69 m/s.

b. The vertical component of the truck's velocity is 21.25 m/s.

Given the following data:

To find both the horizontal and vertical components of the truck's velocity:

a. To find the horizontal component of the truck's velocity:

Mathematically, the horizontal component of velocity is given by the formula:

[tex]V_y = Vsin(\theta)\\\\V_y = 22sin(15)\\\\V_y = 22 \times 0.2588[/tex]

Horizontal component, Vy = 5.69 m/s

b. To find the vertical component of the truck's velocity:

Mathematically, the vertical component of velocity is given by the formula:

[tex]V_x = Vcos(\theta)\\\\V_x = 22sin(15)\\\\V_x = 22 \times 0.9659[/tex]

Vertical component, Vx = 21.25 m/s

Read more: https://brainly.com/question/17742679

Thus, Aristotle believed that the laws governing the motion of the heavens were a different set of laws than those that governed motion on the earth. As we have seen, Galileo's concept of inertia was quite contrary to Aristotle's ideas of motion: in Galileo's dynamics the arrow (with very small frictional forces) continued to fly through the air because of the law of inertia, while a block of wood on a table stopped sliding once the applied force was removed because of frictional forces that Aristotle had failed to analyze correctly.Thus, Aristotle believed that the laws governing the motion of the heavens were a different set of laws than those that governed motion on the earth. As we have seen, Galileo's concept of inertia was quite contrary to Aristotle's ideas of motion: in Galileo's dynamics the arrow (with very small frictional forces) continued to fly through the air because of the law of inertia, while a block of wood on a table stopped sliding once the applied force was removed because of frictional forces that Aristotle had failed to analyze correctly.Thus, Aristotle believed that the laws governing the motion of the heavens were a different set of laws than those that governed motion on the earth. As we have seen, Galileo's concept of inertia was quite contrary to Aristotle's ideas of motion: in Galileo's dynamics the arrow (with very small frictional forces) continued to fly through the air because of the law of inertia, while a block of wood on a table stopped sliding once the applied force was removed because of frictional forces that Aristotle had failed to analyze correctly.Thus, Aristotle believed that the laws governing the motion of the heavens were a different set of laws than those that governed motion on the earth. As we have seen, Galileo's concept of inertia was quite contrary to Aristotle's ideas of motion: in Galileo's dynamics the arrow (with very small frictional forces) continued to fly through the air because of the law of inertia, while a block of wood on a table stopped sliding once the applied force was removed because of frictional forces that Aristotle had failed to analyze correctly.Thus, Aristotle believed that the laws governing the motion of the heavens were a different set of laws than those that governed motion on the earth. As we have seen, Galileo's concept of inertia was quite contrary to Aristotle's ideas of motion: in Galileo's dynamics the arrow (with very small frictional forces) continued to fly through the air because of the law of inertia, while a block of wood on a table stopped sliding once the applied force was removed because of frictional forces that Aristotle had failed to analyze correctly.Thus, Aristotle believed that the laws governing the motion of the heavens were a different set of laws than those that governed motion on the earth. As we have seen, Galileo's concept of inertia was quite contrary to Aristotle's ideas of motion: in Galileo's dynamics the arrow (with very small frictional forces) continued to fly through the air because of the law of inertia, while a block of wood on a table stopped sliding once the applied force was removed because of frictional forces that Aristotle had failed to analyze correctly.Thus, Aristotle believed that the laws governing the motion of the heavens were a different set of laws than those that governed motion on the earth. As we have seen, Galileo's concept of inertia was quite contrary to Aristotle's ideas of motion: in Galileo's dynamics the arrow (with very small frictional forces) continued to fly through the air because of the law of inertia, while a block of wood on a table stopped sliding once the applied force was removed because of frictional forces that Aristotle had failed to analyze correctly.Thus, Aristotle believed that the laws governing the motion of the heavens were a different set of laws than those that governed motion on the earth. As we have seen, Galileo's concept of inertia was quite contrary to Aristotle's ideas of motion: in Galileo's dynamics the arrow (with very small frictional forces) continued to fly through the air because of the law of inertia, while a block of wood on a table stopped sliding once the applied force was removed because of frictional forces that Aristotle had failed to analyze correctly.

Galileo Galilei's mind opens to physics, and nature controls laws that can be mathematically formulated and written in Sagiatori in 1623:

"There is a philosophy in this great book, the book of the universe, which is always open to us, but we can not understand the book if we do not know the language in which it was written and we do not try to learn the letters ... One can not understand even one word of nature and the universe, Human in a large dark lobby ".

2 - Aristotle believed that the nature of the "first engine" eternal is the source of the infinite movement, and that it is valid and exist outside the universe.

Aristotle is one of the ancient Greek scientists who worked on the interpretation of nature based on their competence in observation, reasoning and reasoning, starting with what they considered truthful facts and analyzing them carefully, believing that this would lead them to the correct conclusions.

By following this philosophy, they undoubtedly reached a number of sound conclusions, including that the universe was governed by a particular system, but there was a fundamental weakness in their philosophy, and their ability to observe was limited because they relied only on their abstract senses. . Many scientists, including Aristotle, for example, thought that planets and stars revolve around Earth, an idea that was then self-evident, and Charles Freeman, in his book "Closing Western Thought." Earth is the center of the universe. "

Answer:

C- unbalanced

Explanation:

The arrow to the right has 1000 N less than the rest of the other forces, this means that the forces are unbalanced and the object is moving left.

The sum of the forces along the horizontal component is not equal to that of the vertical, hence the force acting on the car is an unbalanced force

From the given diagram, we have forces acting in the x and y-direction. In order to determine the nature of the forces acting on the car, we will take the sum of the forces acting on the car as shown:

For the horizontal component;

[tex]\sum F_x =+5000 - 6000\\\sum F_x = -1000N[/tex]

Similarly for the vertical component;

[tex]\sum F_y = 6000 - 6000\\\sum F_y = 0N[/tex]

Since the sum of the forces along the horizontal component is not equal to that of the vertical, hence the force acting on the car is an unbalanced force

Learn more here: https://brainly.com/question/20201508

Lets say that:

Eric is E

Sheena is S

Yael is Y

We know that S+2=Y, E= 1/S and that E+S+Y=52. So, we can insert S+2=Y and E= 1/S into our other equation, which would bring us to (1/2S)+(S+2)+S=52. This is equal to 1/2S+S+2+S=52. We then use algebra to get the answer:

Given:

S+2=Y

E=1/S

E+Y+S=52

Equation:

1/2S+S+2+S=52

1/2S+S+S=52

2.5S=50

S=50/2.5

S=20

And since Yael has 2 more points then Yael then we do 20+2 and get 22.

Hope this helps! <3

1)

Answer: A inclined plane and staircase reaching the same height. Work depends on initial and final position only.

Explanation:

The amount of work done does not depend on path length. It depends on initial and final position. It is given by gravitational potential energy.

W = m g h

Where, m is the mass of the object, g is the acceleration due to gravity and h is the height.

Let the mass of the object be m. Two different paths ( one inclines plane and another staircase) are taken to same point. The object would gain same gravitational potential energy because it depends on the height through which the object is taken and not the actual path length.

W ∝ h.

2)

Spring constant can be defined as the ratio of amount of force acting spring  with the displacement caused due to the force. A deformed elastic object has elastic potential energy stored in it which is equal to the work done to deform the object. It is proportional to the spring constant and amount of stretched distance.

Equilibrium is reached when the net force acting on the spring is zero. In equilibrium state, the object has natural extension.  An object is said to possess elastic potential energy  when force is applied and object deforms relative to original equilibrium shape or length.

Putting effort at point IV of this lever gives no mechanical advantage because it requires a greater force.  So the correct answer is C).

Answer:

c

Explanation:

Someone who appears to be lacking in intelligence according to intelligence testing scores but seems to excel in other domains is said to have SAVANT SYNDROME

Answer:

Someone who appears to be lacking in intelligence according to intelligence testing scores but seems to excel in other domains is said to have SAVANT SYNDROME

Explanation:

Savant Syndrome is a set of anomalous cognitive symptoms where people suffer from a major left hemisphere disability; however, they can perform surprisingly well some tasks that involve the right hemisphere. People with savant syndrome develop talents, that is, extraordinary abilities in particular, concrete and peculiar.

In other words, according to this syndrome, some people with mental disorders and despite their physical, mental or motor disabilities, possess a surprising ability or specific mental abilities. That is, it is a condition in which a person with a mental disorder (such as an autism spectrum disorder) demonstrates a deep and prodigious ability or ability, far superior to what would be considered normal.

People with Savant Syndrome may have neurodevelopmental disorders (especially autism spectrum disorders) or brain injuries.

The most common abilities of the Savant are centered in Art (music, painting and sculpture), Calculation of dates, Mathematical calculation and mechanical and spatial skills.

Answer:

Momentum (p) = m . v  Kg-m/s

                          = 30 × 5

                      p  = 150 Kg .m/s

A pendulum swings performing back and forth motion and having a kinetic energy of 400 J then both the kinetic and potential energy are decreasing. Hence, option A is correct.

The energy that an object has as a function of motion is known as kinetic energy. It is described as the effort required to move a surplus body from rest to the indicated velocity. The body will hold onto the kinetic energy it acquired during its acceleration until its speed changes.

The body exerts the same amount of effort when slowing from its current pace to a condition at rest. Formally, angular momentum is any term in the Lagrangian of a system having a time derivative. Mathematically, it is represented as [tex]\frac{1}{2} mv^2[/tex].

Therefore, both the kinetic and potential energy is decreasing, so option A is correct.

To know more about Kinetic energy :

https://brainly.com/question/26472013

#SPJ2

Final answer:

The statement that is not true is 'both the kinetic and potential energy are decreasing,' as this violates the conservation of energy in a swinging pendulum. Energy is transferred from potential to kinetic and vice versa, not decreased simultaneously.

Explanation:

The question relates to the conservation of energy in a swinging pendulum, a common topic in high school physics. Specifically, it concerns the relationship between kinetic energy and potential energy during the pendulum's motion.

When a pendulum swings back and forth, its kinetic energy and potential energy are constantly interchanged. At the highest points of the swing, where the pendulum momentarily stops before changing direction, the kinetic energy is zero and all energy is stored as potential energy. On the other hand, at the lowest point in its path, where the pendulum moves fastest, the potential energy is at its minimum and kinetic energy is at its maximum.

Given this information, let us examine the provided statements:

A- This statement is incorrect because, at a particular point, both energies cannot be decreasing at the same time since energy is being transferred from one form to the other.

B- This is true, as the kinetic energy is zero when the pendulum reaches its highest point.

C- When the pendulum's kinetic energy is zero at its highest point, the potential energy equals the total mechanical energy, which would be 400 J if no energy were lost to friction or air resistance.

D- This statement is correct as it follows the principle of energy conversion, where an increase in potential energy is matched by a corresponding decrease in kinetic energy and vice versa.

Therefore, the statement that is not true is A - both the kinetic and potential energy are decreasing. The potential energy increases when the pendulum reaches the highest points of its swing (where the kinetic energy decreases to zero), and the kinetic energy increases as the pendulum swings downward and potential energy decreases.

The answer is option C .Because as the direction of the boy changes ;velocity changes .

Answer

Correct answer is option C .

Explanation:

Option A cannot be correct option because in this case only distance traveled and time is given we are not sure whether velocity is changing or not.

Option B

In this case girl travel with constant velocity so it cannot be accelerated motion

Option C

Correct option is C. Because as the direction of the boy changes that time velocity changes and rate of change of velocity with respect to time is known as acceleration

Option D

In this case also only distance and time is given we cant say whether it is accelerated motion or not

Her average speed would be 30 kilometers in a hour.

Answer: Her average speed would be 30 kilometers per hour because 60 divided by two is 30 which is how you can calculate the average speed if desired.

Hope this helps!  :)

Explanation:

The correct tool a student can use to identify what type and how many atoms are in a chemical compound is the International Union of Pure and Applied Chemistry (IUPAC) nomenclature.

The IUPAC nomenclature is a systematic method of naming chemical compounds based on their molecular structure. It provides a standardized way to communicate information about the composition and structure of molecules, including the types of atoms present and their arrangement. By using IUPAC names, one can deduce the molecular formula, which indicates the number and type of atoms in the compound.

For example, the IUPAC name for the compound ethanol is ethyl alcohol. From this name, we can determine that the compound contains two carbon atoms (eth- indicates an ethyl group, C2H5), one oxygen atom (the suffix -ol indicates an alcohol group, -OH), and six hydrogen atoms (since the ethyl group has five hydrogen atoms and the alcohol group has one). Thus, the molecular formula for ethanol is C2H6O, which accurately represents the number and type of atoms in the compound.

Common names and chemical names provided by societies like the National Chemistry Society can sometimes be used to identify compounds, but they may not always provide clear information about the molecular structure or the exact number of each type of atom. These names can be ambiguous or vary by region and language, whereas IUPAC nomenclature is internationally recognized and provides a clear and unambiguous description of the compound's composition.

Therefore, the IUPAC nomenclature is the most reliable tool for a student to use during a test to determine the type and number of atoms in a chemical compound.

Gravitational potential energy of the car is given by formula

[tex]U = mgh[/tex]

here m = mass of the car

g = gravitational field intensity

h = height of the car from reference point

so here from above formula we can say that if height of the car from reference is zero the gravitational potential energy will be zero

So here we generally took the reference point to be at bottom on the ground

so here also the gravitational potential energy will be zero at the ground

so correct answer will be

C)at the bottom of the hill

Answer:

C) up a hill and then rolling back down the other side.

Explanation:

The forces on the  y axis are:

N-mgcos(60)=0   , wich becomes

N=mgcos(60)

Rember that the friction force is always contrary to the motion of an object and its formula is  f=μ * N

The forces in the x axis are:

-f + mgsin(60)= m * a

-μ*mgcos(60) + mgsin(60)=m*a  ,

μ = ( m*a - mgf=μ[sin(60) )/ ( mgcos(90) )