the half life of a certain substance is 25 years. How long will it take for a sample of this substance to decay to 90% of its original amount ...?
Suppose that you want to move a heavy box with mass 30.0 across a carpeted floor. You try pushing hard on one of the edges, but the box does not move. Suppose that you are pushing against the box from an angle 30.0 above horizontal with a force of magnitude 240 . What is the magnitude of the friction force acting on the box? ...?
Which type of wave is characterized by circular motion?
A. transverse wave
B. longitudinal wave
C. primary wave
D. surface wave
Answer:
D. surface wave
Explanation:
A) Transverse Waves
As the energy is propagated through the medium and then medium particles moves to and fro perpendicular to wave propagation then this is known as transverse waves.
B) Longitudinal waves
As energy is propagated through the medium and then medium particles oscillates in direction of wave propagation then it is known as longitudinal waves.
C) Primary waves
these waves are due to compression and expansion of medium and it can travel at high speed. It is moreover similar to longitudinal waves
D) Surface Waves
In these type of waves the disturbance or energy is propagated through the medium particles on the surface of the water in the shape of concentric circles.
So surface wave is characterized by circular motion
Read each description below. Choose the force diagram (free-body diagram) that best represents the description. You may neglect the effects of air resistance. |
A. Mark's physics book is on the desk. Mark pushes horizontally (from the side) on the book, but the book does not move. |
B. Kendall's physics book is on the desk. Kendall pushes horizontally (from the side) on the book, and the book moves across the desk at a constant speed. |
C. Jenny pushes a cart at constant velocity down the grocery store aisle. |
D. Eddy is driving his Camaro down a straight, level road while on cruise control. |
E. Ryan is accelerating his Dakota down a straight, level road. |
F. Jackie's Viper is parked on the shoulder of the road while she changes a flat tire. |
Answer:
A. Mark's physics book is on the desk. Mark pushes horizontally (from the side) on the book, but the book does not move.
DIAGRAM B
B. Kendall's physics book is on the desk. Kendall pushes horizontally (from the side) on the book, and the book moves across the desk at a constant speed. |
DIAGRAM B
C. Jenny pushes a cart at constant velocity down the grocery store aisle.
DIAGRAM B
D. Eddy is driving his Camaro down a straight, level road while on cruise control.
DIAGRAM B
E. Ryan is accelerating his Dakota down a straight, level road.
DIAGRAM C
F. Jackie's Viper is parked on the shoulder of the road while she changes a flat tire.
DIAGRAM A
Explanation:
A. Since the book does not move even after being pushed it is leveled in all forces.
B. Since it is pushed at a constant speed, all forces are equal.
C. Since it is pushed at a constant speed, all forces are equal.
D. Since it is driven at a constant speed on cruise control, all forces are equal.
E. Since he is accelerating, which means it is being driven much faster than the friction that is pushing the car back, the forces are unequal.
F. The only forces acting on the is the car on the ground and the ground on the car, there is no other forces of friction pushing it back or the car being pushed forward. It is parked.
In option A, the book does not move, so the force diagram would show the normal force and the force of friction. In option B, the book moves at a constant speed, so the force diagram would show the normal force and the force of friction in the same direction as the applied force. Option C involves a cart moving at constant velocity, which would have a force diagram showing the forward push and the force of friction. Options D and E involve cars on level roads, with D having a balanced force diagram and E having unbalanced forces causing acceleration. Option F involves a parked car with a balanced force diagram.
Explanation:The force diagram that best represents the scenario described in option A, where Mark's physics book is on the desk and Mark pushes horizontally on the book but it does not move, would be a free-body diagram showing only the normal force and the force of friction acting on the book. Since the book does not move, the forces are balanced, with the force of friction equal in magnitude and opposite in direction to the horizontal force applied by Mark.
In option B, where Kendall's physics book is on the desk and Kendall pushes horizontally on the book and it moves across the desk at a constant speed, the force diagram would also include the normal force and the force of friction, but the force of friction would be in the same direction as Kendall's applied force, since the book is moving. The forces are balanced and the net force is zero.
In option C, where Jenny pushes a cart at constant velocity down the grocery store aisle, the force diagram would include a force in the forward direction representing Jenny's push, as well as the force of friction opposing the motion. The forces are balanced and the net force is zero.
In option D, where Eddy is driving his Camaro down a straight, level road while on cruise control, there would be a force diagram showing the force of the engine pushing the car forward, the force of friction opposing the motion, and the normal force. The forces are balanced and the net force is zero.
In option E, where Ryan is accelerating his Dakota down a straight, level road, the force diagram would include the force of the engine pushing the car forward, the force of friction opposing the motion, and the normal force. The net force is non-zero, as the forces are unbalanced and causing the acceleration.
In option F, where Jackie's Viper is parked on the shoulder of the road while she changes a flat tire, there would be a force diagram showing only the force of gravity acting on the car, the normal force from the ground, and the force of friction from the ground. The forces are balanced and the net force is zero.
how to solve arctan[tan(7pi /4)] ...?
The solution to arctan[tan(7π/4)] is -(π/4).
How to find arctan?To solve the expression arctan[tan(7π/4)], simplify it using the properties of trigonometric functions and inverse trigonometric functions.
First, examine the value of tan(7π/4). The tangent function has a period of π, meaning it repeats its values every π radians.
Therefore, find an equivalent angle within the range of one period (0 to π) that has the same tangent value.
7π/4 can be reduced to 3π/4 by subtracting 2π, as it falls within the same period.
Now, arctan[tan(3π/4)].
The arctan function (or inverse tangent) "undoes" the tangent function, giving us the original angle. However, it's important to note that arctan has a range of -π/2 to π/2.
The angle 3π/4 falls within the range of π/2 to 0, so its corresponding angle within the range of arctan is -(π/4).
Therefore, the solution to arctan[tan(7π/4)] is -(π/4).
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At noon, ship A is 45 miles due west of ship
B. Ship A is sailing south at 5 mph while ship
B is sailing north at 15 mph.
At what speed is the distance between the
ships changing at 3:00 pm?
If the speed of a ball increased from 1m/s to 4m/s, by how much would the kinetic energy increase
A disk with mass m = 5.7 kg and radius R = 0.43 m hangs from a rope attached to the ceiling. The disk spins on its axis at a distance r = 1.56 m from the rope and at a frequency f = 20 rev/s (with a direction shown by the arrow).
What is the magnitude of the angular momentum of the spinning disk? ...?
Answer : [tex]L=66.18\ kgm^2/s[/tex]
Explanation :
It is given that,
Mass, m = 5.7 kg
radius, R = 0.43 m
frequency, f = 20 rev/s
Angular momentum, [tex]L=I\omega[/tex]
I is the moment of inertia of disk, [tex]I=\dfrac{MR^2}{2}[/tex]
we know that, [tex]\omega = 2\pi \nu[/tex]
so, [tex]L=MR^2\pi \nu[/tex]
[tex]L= 5.7\ kg\times (0.43\ m)^2\times3.14\times 20\ rev/s[/tex]
[tex]L=66.18\ kgm^2/s[/tex]
Hence, the magnitude of angular momentum of spinning disk is [tex]66.18\ kgm^2/s[/tex].
What statement is true because of Newton's Second Law?
A. When the Net force of an abject decreases, the acceleration doesn't change
B. When the net force of an object increases, the acceleration decreases
C. When the net force of an object decreases, the acceleration decreases
D. When the net force of an object decreases, the acceleration increases
was the answer even right
An example of a high energy electromagnetic wave is
a radio wave
a red light wave
an x-ray
an infrared wave
------------------------------------------
Give an example of an energy transformation.
------------------------------------------
When heat is transferred to a substance explain why the temperature goes up
An element's atomic number is 45. How many protons would an atom of this element have?
Is my answer correct?
question
Scott was watching the electrician install a new light fixture. Scott noticed that when he was finished, he carefully wrapped some wires with plastic caps and black plastic tape. Select the best explanation of why the electrician would wrap electrical wires with plastic products.
answer I chose
The electrical wires are made of metal, which conducts electricity. In order to make the wiring safe, he would wrap the exposed wire with plastic materials, which are good insulators. This keeps the flow of electricity contained to the light fixture and wiring.
Answer:
Yes, the answer is correct.
Explanation:
Plastic is a good insulator of electricity and it prevents electric current from flowing into any living being that may come into contact with that wiring. Hence, the plastic tape and caps prevent any such contact with the live wiring making the entire system safe to be around.
Viruses are different from bacteria in that
A/ they can remain dormant on non-living surfaces
B/ they can be found just about anywhere
C/ they can infect just about every form of life
the answer to the question is A.
Answer:
a
Explanation:
Jenny wants to determine if a new brand name washing detergent is better than her old detergent she washed ten dirty t-shirts with the new washing detergent and ten dirty t-shirts with the old detergent identify the dependent and independent variables for this experiment
the independent varible is old and new and the dependent variable is 20 T-shirts can I get brainliest
Explanation:
An independent variable is a variable whose value does not depend on any other factor. Whereas a dependent variable is a variable whose value depends on another factor.
Hence, in the given situation old and new detergent are independent variables as they do not depend on any other factor.
On the other hand, 20 dirty T-shirts are dependent variable because they get clean only if the detergent is strong enough.
An athlete is working out in the weight room. He steadily holds 50 kilograms above his head for 10 seconds. Which statement is true about this situation?
The athlete isn’t doing any work because he doesn’t move the weight.
The athlete isn’t doing any work because he doesn’t hold the weight long enough.
The athlete is doing work because he prevents the weight from falling downward.
The athlete is doing work because 50 kilograms is a significant load to lift.
Answer: The true statement form the given statements is "the athlete is not doing any work because he does not move the weight.".
Explanation:
The formula for work done is as follows,
[tex]W = Fscos\theta[/tex]
Here, F is the force, s is the displacement and theta is the angle between force and displacement.
In the given problem, an athlete holds 50 kg on his head for 10 seconds. The angle between force and displacement is 90 degree.
In this case, the work done is zero.
Therefore, the athlete is not doing any work because he does not move the weight.
An atom that has 84 protons and 86 neutrons undergoes a reaction. At the end of the reaction, it has 82 protons and 84 neutrons. What happened to the atom?
The atom underwent alpha decay, emitting 2 protons and 2 neutrons, transforming from polonium (Po-170) to lead (Pb-166).
The atom originally was a polonium (Po) atom with 84 protons and 86 neutrons (Po-170). It underwent alpha decay, a type of radioactive decay where it emitted an alpha particle, consisting of 2 protons and 2 neutrons. As a result, the atom transformed into a lead (Pb) atom with 82 protons and 84 neutrons (Pb-166).
This process reduced the atomic number by 2 and the mass number by 4, leading to the formation of a different element. Alpha decay occurs when an unstable nucleus emits an alpha particle, reducing both its atomic number and mass number. It is a natural process observed in certain heavy and unstable elements as they strive to achieve a more stable configuration, often resulting in the formation of a different element.
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Who was the first woman to go to space?
Judy Garland
Sally Ride
Valentina Tereshkova
Neil Armstrong
Yuri Gagarin
A ball is thrown from an initial height of 3 ft with an initial upward velocity of 27ft/s The balls height h (in feet) after t seconds is given by the following. h=3+27t-16t^2. Find all values of t for which the balls height is 13 ft. ...?
Answer:
t = 0.55 s and t = 1.14 s
Explanation:
as we know that height in terms of time is given as
[tex]h = 3 + 27t - 16 t^2[/tex]
now we have to find the time at which its height is h = 13 ft
so here we can say
[tex]13 = 3 + 27 t - 16 t^2[/tex]
[tex]16 t^2 - 27 t + 10 = 0[/tex]
[tex]t = \frac{27 \pm \sqrt{27^2 - 4(16)(10)}}{2(16)}[/tex]
[tex]t = \frac{27 \pm 9.43}{32}[/tex]
[tex]t = 1.14, 0.55[/tex]
so it will be at h = 13 ft height at t = 0.55 s and t = 1.14 s
which flow chart below shows the energy conversions that occur when you turn on your laptop
A: electrical> light,sound and thermal
B: thermal> light,sound and electrical
C: electrical> light,sound and nuclear
D: thermal> sound,nuclear and electrical
Answer: Option A.
Explanation: When you turn on your laptop, you are allowing the electrical energy to flow in the components of the laptop.
Once it is on, you can see that your laptop is generating light (from the screen) and sound (maybe if you are listening to music or something). And as the electricity is passing through the components of the laptop, the components start to raise their temperature, and then you also are generating thermal energy.
What is the pH scale used for? a. Measures hydroxide ion concentration (strength of the acid or base) b. Measures hydronium ion concentration (strength of the acid or base)
Elements in Group 18, at the far right of the periodic table, are called what?
Transition Metals
Noble Gases
Alkaline Metals
Halogens
A ball that has a mass of 0.25 kg spins in a circle at the end of a 1.6 m rope. The ball moves at a tangential speed of 12.2 m/s.
For this case what we must do is calculate the centripetal force of the object.
By definition, the centripetal force is given by:
[tex] F = m(\frac{v^2}{r})
[/tex]
Where,
v: tangential speed
r: radius of the circular path
m: mass of the object
Substituting values we have:
[tex] F = 0.25 * (\frac{12.2 ^ 2}{1.6})
F = 23.26
[/tex]
Answer:
The centripetal force of the ball is given by:
[tex] F = 23.26 N [/tex]
Answer:
The answer is B) 23 N
Explanation:
I got the correct answer on the pre-test.
An object moving with constant acceleration near the surface of the earth is influenced by
Final answer:
An object in free-fall near Earth's surface experiences a constant acceleration due to gravity, denoted by 'g' and averaging 9.80 m/s². This allows for uniform predictions of an object's motion when air resistance is negligible.
Explanation:
An object moving with constant acceleration near the surface of the Earth is primarily influenced by the acceleration due to gravity. This acceleration, commonly represented by the symbol g, has an average value of 9.80 m/s². It is important to note that this value can be considered constant when air resistance is negligible, thus letting us apply kinematics equations to any such falling object to predict its motion. The constant nature of acceleration due to gravity allows for a wide range of interesting physical problems and applications.
It is essential to understand that the force of gravity causes objects to fall towards the Earth's center, and it is this force that imparts uniform acceleration to free-falling objects. Furthermore, gravity's influence is such that even varying factors like latitude, altitude, and geographical differences only slightly alter its magnitude, and for most practical purposes in high school physics, the average value of 9.80 m/s² is used.
Which law represent a balanced chemical equation?
Answer: Law of Conservation of Mass
Explanation:
A balanced chemical equation represents the 'Law of Conservation of Mass '
Law of Conservation of Mass states that 'in chemical reaction mass can neither be created nor be destroyed '.The total mass of the reactant in chemical reaction is equal to the total mass of the products formed in a chemical reaction.
For example : [tex]2H_2+O_2\rightarrow 2H_2O[/tex]
Mass of reactants = Mass of the products
mass of the reactants = 2(2 × 1) + (2 × 16) = 36 g/mol
Mass of the products = 2[(2 × 1 ) + (1 × 16)] = 36 g/mol
As from the above calculations, we find that the mass of the reactants is equal to the mass of the products. Hence, this equation follows law of conservation of mass.
A balanced chemical equation adheres to the law of conservation of mass, which asserts that matter is neither created nor destroyed in a chemical reaction.
Explanation:Law Behind Balanced Chemical Equations:
The law that is represented by a balanced chemical equation is the law of conservation of mass. This fundamental law states that matter cannot be created or destroyed in a chemical reaction. Therefore, a balanced chemical equation ensures that the number of atoms for each element is equal on both sides, reflecting the unchanging total mass in the reaction.
To illustrate, look at the equation for the reaction of hydrogen with oxygen to form water: 2H₂(g) + O₂(g) → 2H₂O(l). This equation is balanced because it has the same number of hydrogen atoms (4 H atoms) and oxygen atoms (2 O atoms) on both the reactant and product sides.
Balancing chemical equations involves adjusting the coefficients before each substance so that the total number of atoms of each element is the same on both sides of the equation. This practice aligns with the law of conservation of matter, ensuring that the mass before and after the reaction remains constant, and only the arrangement of atoms changes to form new substances.
What is the weight of a person whose mass is 72kg?
To solve this we must be knowing each and every concept related to mass. Therefore, 705.6N is the weight of a person whose mass is 72kg.
What is mass?The density and kind of atoms in any particular item are described by mass, which is a scientific word. The kilogram (kg) is the SI measurement of mass, however mass could also be measured using pounds (lb).
Consider a pillowcase packed with feathers as well as a comparable pillowcase loaded with bricks to rapidly grasp the notion of mass. The bricks have a higher mass because of atoms in them are heavier and denser. As a result, even when the pillowcases have the same size and therefore are filled with the same extent, one has significantly more mass compared to the other.
weight= mass× acceleration due to gravity
weight= 72kg×9.8
=705.6N
Therefore, 705.6N is the weight of a person whose mass is 72kg.
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the amount of matter in an object is called
A 100 g ball moving to the right at 4.0 m/s collides head-on with a 200 g ball that is moving to the left at 3.0 m/s.
If the collision is perfectly elastic, what are the speeds of each ball after the collision?
The final speed of the 100-g ball is about 5.3 m/s to the left
The final speed of the 200-g ball is about 1.7 m/s to the right
[tex]\texttt{ }[/tex]
Further explanationNewton's second law of motion states that the resultant force applied to an object is directly proportional to the mass and acceleration of the object.
[tex]\large {\boxed {F = ma }[/tex]
F = Force ( Newton )
m = Object's Mass ( kg )
a = Acceleration ( m )
Let us now tackle the problem !
[tex]\texttt{ }[/tex]
Given:
mass of ball 1 = m₁ = 100 g
initial velocity of ball 1 = u₁ = 4.0 m/s
mass of ball 2 = m₂ = 200 g
initial velocity of ball 2 = u₂ = -3.0 m/s
Asked:
final velocity of ball 1 = v₁ = ?
final velocity of ball 2 = v₂ = ?
Solution:
Firstly , we will use Conservation of Momentum Law as follows:
[tex]m_1u_1 + m_2u_2 = m_1v_1 + m_2v_2[/tex]
[tex]100(4.0) + 200(-3.0) = 100v_1 + 200v_2[/tex]
[tex]-200 = 100v_1 + 200v_2[/tex]
[tex]-2 = v_1 + 2v_2[/tex] → Equation 1
[tex]\texttt{ }[/tex]
If the collision is perfectly elastic , then:
[tex]u_1 - u_2 = v_2 - v_1[/tex]
[tex]4.0 - (-3.0) = v_2 - v_1[/tex]
[tex]7.0 = v_2 - v_1[/tex] → Equation 2
[tex]\texttt{ }[/tex]
Let's solve the two Equations above:
(Equation 1) + (Equation 2) ↓
[tex]-2 + 7.0 = (v_1 + 2v_2) + (v_2 - v_1)[/tex]
[tex]5.0 = 3v_2[/tex]
[tex]v_2 = 5.0 \div 3[/tex]
[tex]v_2 = 1\frac{2}{3} \texttt{ m/s}[/tex]
[tex]v_2 \approx 1.7 \texttt{ m/s}[/tex]
[tex]\texttt{ }[/tex]
[tex]-2 = v_1 + 2v_2[/tex]
[tex]-2 = v_1 + 2(1\frac{2}{3})[/tex]
[tex]v_1 = -2 - 3\frac{1}{3}[/tex]
[tex]v_1 = -5\frac{1}{3} \texttt{ m/s}[/tex]
[tex]v_1 \approx -5.3 \texttt{ m/s}[/tex]
[tex]\texttt{ }[/tex]
Learn moreImpacts of Gravity : https://brainly.com/question/5330244Effect of Earth’s Gravity on Objects : https://brainly.com/question/8844454The Acceleration Due To Gravity : https://brainly.com/question/4189441Newton's Law of Motion: https://brainly.com/question/10431582Example of Newton's Law: https://brainly.com/question/498822[tex]\texttt{ }[/tex]
Answer detailsGrade: High School
Subject: Physics
Chapter: Dynamics
[tex]\texttt{ }[/tex]
Keywords: Gravity , Unit , Magnitude , Attraction , Distance , Mass , Newton , Law , Gravitational , Constant
If energy decreases in one part of a system, what will happen?
a. energy will be created in the system.
b. energy will be destroyed in the system.
c. energy will increase in another part of the same system.
d. energy will decrease in another part of the same system.
If energy decreases in one part of a system, energy will increase in another part of the same system. Therefore, option C is correct.
What is energy ?Energy can be transmitted from an object to do work and is thought of as a quantitative feature. Thus, we might characterize energy as the capacity to engage in any kind of physical action. As a result, the simplest way to describe energy is as the capacity for work.
When a system is heated or has work done on it by its environment, the internal energy of the system is constantly raised. Let's examine two situations that lead to an increase in a system's internal energy.
The process can continue if the free energy drops. The reaction can't continue if the free energy rises. If the system's free energy falls, a reaction is encouraged.
Thus, option C is correct.
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What is meant by the following statement? "Acceleration is inversely proportional to mass." Acceleration decreases as mass decreases. Acceleration and mass are opposites. Acceleration increases as mass decreases. Acceleration is not affected by mass
C. Acceleration Increases As Mass Decreases.
If a star contains a certain element, it can be determined by studying the star’s
A.Emission Spectrum
B.Corona
C.Sunspot Activity
D.Main Sequence