a=Δv/Δt=(30.0-18.0)/8.0=12.0/8.0=1.5 m/s²
Answer:
Acceleration of the car, [tex]a=1.5\ m/s^2[/tex]
Explanation:
It is given that,
Initial speed of the car, u = 18 m/s
Final speed of the car, v = 30 m/s
Time taken, t = 8 s
We need to find the acceleration of the car. Let it is given by a. It can be calculated using the first equation of motion.
[tex]v=u+at[/tex]
Where
a is the acceleration of the car.
[tex]a=\dfrac{v-u}{t}[/tex]
[tex]a=\dfrac{30-18}{8}[/tex]
[tex]a=1.5\ m/s^2[/tex]
So, the magnitude of the car's acceleration is [tex]1.5\ m/s^2[/tex]. Hence, this is the required solution.
What effect would the temperature have on the time kept by a pendulum clock if the pendulum rod increase in length with an increase in temperature
As we know the time period of pendulum is given by the equation
[tex]T = 2\pi \sqrt{\frac{L}{g}}[/tex]
so here
L = length of the pendulum
Now on increasing the temperature due to thermal expansion the length of the pendulum will increase and due to this the time period of the pendulum will also increase
Now due to increase in time period of the pendulum the clock will become slow and it will give incorrect time due to this increase in temperature
Thermal expansion increases the pendulum period, and the clock will lose time
Further explanationSimple Harmonic Motion is the motion of an object (repetitive movement) through its equilibrium point where the frequency of vibrations / oscillation per second is constant
The motion that occurs in the pendulum is one example of simple harmonic motion
Terms used:
Deviation (y): the object's distance from the balance point Amplitude (A): maximum deviation frequency (f): number of vibrations at any time Period (T): the amount of time in one vibrationWhereas the relationship T and f:
[tex]\displaystyle T=\frac{1}{f}\\\\f=\frac{n}{t}[/tex]
n = number of vibrations / oscillation
t = time (s)
Formula used:
[tex]\large{\boxed{\bold{T=2\pi \sqrt{\frac{L}{g} }}}\rightarrow \frac{1}{f}=2\pi \sqrt{\frac{L}{g} }[/tex]
From this formula shows that the period is proportional to the length of the pendulum rod . The longer the pendulum rod , the greater the amount of time in one vibration
If thermal expansion occurs in the pendulum clocks, the pendulum rod changes in length ,proportional to the temperature change, and increases the pendulum period, so the clock will lose time
Learn moreThe distance of the elevator
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Rank the pendulums according to the number of complete cycles
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the average velocity
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The part of the eye responsible for most of the refraction of incoming light is the _____.
lens
retina
optic nerve
cornea
Question: The part of the eye responsible for most of the refraction of incoming light is the _____.
Answer: lens
Explanation: this is because your eye lens reflects of light from your eyes like when the sunlight shines aff a pair of glasses it makes fire
question answered by
(jacemorris04)
Answer:
LENSExplanation:
If you know the amount of air pressure exerted on a tabletop, how can you calculate the force exerted on the tabletop? Multiply the air pressure by the area of the tabletop. Divide the air pressure by the area of the tabletop. Divide the area of the tabletop by the air pressure. Add the air pressure and the area of the tabletop.
Answer:
Multiply the air pressure by the area of the tabletop.
Explanation:
The relationship between pressure, force and area is given by:
[tex]p=\frac{F}{A}[/tex]
where in this case, p is the air pressure, F is the force exerted and A the area of the tabletop. By re-arranging the equation, we can solve for F, the force exerted:
[tex]p=\frac{F}{A}\\p\cdot A=\frac{F}{A}\cdot A\\pA=F[/tex]
So, the correct answer is:
The force exerted on the tabletop can be found by multiplying the air pressure by the area of the tabletop.
Which waves can travel through a vacuum? A) light waves Eliminate B) ocean waves C) sound waves D) mechanical waves
Electromagnetic waves are the waves which can also travel through the vacuum. Example of electromagnetic waves are - Radio waves , micro waves, Infrared waves, Light (visible portion of electromagnetic spectrum), Ultraviolet rays, Xrays and gamma rays.
Hence A that is light waves is the correct option.
The answer is A! I hope this helps!
What is the resulting value for the Hubble constant?Write your answer in scientific notation
[tex]\bf{Given : Hubble\;Constant(H_0) = 73(\frac{km}{s \times Mpc})}[/tex]
[tex]\bf{Given : Conversion\;Factor = (\frac{1Mpc}{3.086 \times 10^1^9\;km})}[/tex]
[tex]\bf{\implies Resulting\;Hubble\;Constant = 73(\frac{km}{s \times Mpc})(\frac{1Mpc}{3.086 \times 10^1^9\;km})}[/tex]
[tex]\bf{\implies Resulting\;Hubble\;Constant = 73(\frac{1}{s \times 3.086 \times 10^1^9})}[/tex]
[tex]\bf{\implies Resulting\;Hubble\;Constant = (\frac{23.65}{s \times 10^1^9})}[/tex]
[tex]\bf{\implies Resulting\;Hubble\;Constant = 2.365 \times 10^-^1^8(1/s)[/tex]
A slinky is stretched across a classroom and moved up and down at a frequency of 3 Hz. If the corresponding wave velocity is 6.6 m s , determine the wavelength of the slinky wave.
A) 0.45 m
B) 2.2 m
C) 9.9 m
D) 19.8 m
For any wave, Wavelength = (speed) / (frequency).
So the Slinky Wavelength = (6.6 m/s) / (3 / sec)
Wavelength = 2.2 meters .
It takes the compression in the wave 2.2 seconds to travel the length of the classroom.
A toy car of mass 0.15kg accelerates from a speed of 10 cm/s to a speed of 15 cm/s. What is the impulse acting on the car?
A. 7.5 mN s
B. 37.5 mN s
C. 0.75 N s
D. 3.75 N s
If you could explain how you got it I would appreciate that
v=v2-v1=15-10=5 cm/s
p=mv=0.15•5=0.75 kg•cm/s
Answer : The correct option is, (A) 7.5 mN.s
Explanation :
Impulse : It is defined as the force applied to an object for a certain amount of time.
Formula used :
[tex]I=F\times \Delta t[/tex]
As we know that:
[tex]F=m\times \Delta a\\\\\Delta a=\frac{\Delta v}{\Delta t}[/tex]
Thus, formula of impulse will be:
[tex]I=m\times \Delta v[/tex]
where,
I = impulse = ?
m = mass = 0.15 kg
[tex]\Delta v[/tex] = change in speed of velocity = [tex]v_{final}-v_{initial}=15cm/s-10cm/s=5cm/s=0.05m/s[/tex] (1 m = 100 cm)
Now put all the given values in the above formula, we get:
[tex]I=(0.15kg)\times (0.05m/s)[/tex]
[tex]I=0.0075kg.m/s=0.0075N.s=7.5mN.s[/tex] (1 N.s = 1000 mN.s)
Therefore, the impulse acting on the car is, 7.5 mN.s
Assuming no friction form air, how far will a dropped rock fall in 10 seconds
Given that
time (t) = 10 s ,
(S) = ?
We know that S = ut+ 1/2 a.t² m
since free fall and no air friction,
a = g = 9.81 m/s² ; initial velocity u= 0
S = 0 + [1/2 × 9.81 ×10²]
S = 490.5 m
how do positive and negative acceleration differ
Positive acceleration increases speed, negative acceleration is decreasing speed.
For example on a car the gas pedal would be positive acceleration and brake would be negative.
Answer: Positive acceleration represents an object speeding up; negative acceleration represents an object slowing down.
Explanation:
hope it helped xx
Examine the droppler effect illustration above. Assume the red dot is a police car with its siren on. Which direction is the police car traveling
Something is missing in question. But I will try to explain you about Doppler effect to reach your answer.
Answer:
It is defined as "an increase in the frequency of sound, light or other waves as the source or observer moves towards each other".This effect causes the sudden change in pitch noticeable in passing siren. You hear a siren from a few blocks away. The source is a police car that is racing in your direction. As the car approaches, zooms past you, and then speeds off into the distance, the sound of its siren keeps changing in pitch. First the siren gets higher in pitch, and then it suddenly gets lower.
If you on USA TEST prep the answer was "RIGHT"
If you need to drive from Dallas, Texas, to Salt Lake City, Utah, (about 1500 miles), and the speed limit is 60 miles per hour most of the way, what is the least amount of time you will need?
A.
4 hours
B.
25 hours
C.
2.5 hours
D.
90,000 hours
Assuming (for the least amount of time) that it is 60mph all the way through. Divide the two numbers
1500/60 = 25
B. 25 hours is your answer
~
25 hours.
All you have to do to find out is divide 60 into 1500 and you will get B:25 hours
What force is needed to keeps 20kg box moving at a constant velocity when the mk is 0.3021 and the force is applied level to the ground
Answer:
59.2 N
Explanation:
According to Newton's second law, the resultant of the forces acting on the box must be equal to the product between the box's mass and its acceleration:
[tex]F_{net}=ma[/tex]
However, the box is moving at constant velocity, so its acceleration is zero:
a = 0
Therefore, the net force along the direction of motion (parallel to the surface) must be zero.
We have two forces acting along the direction parallel to the ground:
- The applied force, F
- The frictional force, [tex]\mu mg[/tex], in the opposite direction, with [tex]\mu = 0.3021[/tex] being the coefficient of friction, m = 20 kg the mass of the box and g = 9.8 m/s^2
Therefore, the equation of motion becomes:
[tex]F-\mu mg=0[/tex]
And solving for F, we find:
[tex]F=\mu mg=(0.3021)(20 kg)(9.8 m/s^2)=59.2 N[/tex]
If there is no pressure, water will
A. Stand still
B. Move quickly
C. Become warmer
D. Change into gas
Under the condition of no pressure, water will change into gas. This phase change can occur by boiling if the water is in a liquid state or sublimation if it is a solid, as there is no liquid phase at extremely low pressures.
Explanation:If there is no pressure, water will change into gas. This process is understood through the physical properties of water and its behavior under different temperature and pressure conditions. When energy is added into a system containing water, the water molecules begin to move faster. As more energy is put in, the temperature rises until it reaches the boiling point, which is a fixed temperature specific to each substance where it changes from liquid to gas.
However, at extremely low pressures, the scenario changes. There is no liquid phase for water below 0.00600 atm, implying that water can either be a gas or a solid. In these conditions, water undergoes a phase change known as sublimation, where it transitions directly from a solid to a gas without becoming liquid.
Thus, under the condition of 'no pressure,' which is an extreme low-pressure scenario, water will opt for the gaseous state, either by boiling from the liquid state if it originally was a liquid, or by sublimating if it was a solid.
In the absence of pressure, water will turn into a gas through the process of sublimation, where at extremely low pressures below 0.00600 atm, it can directly transition from a solid to a gas.
Explanation:If there is no pressure, water will change into gas. This phenomenon is because, at sufficiently low pressures, water has no liquid phase and can exist either as a gas or as a solid. When water molecules receive enough kinetic energy, such as at their boiling point, they overcome intermolecular forces and transition to the gas phase. At pressures below approximately 0.00600 atm, this transition happens directly from a solid to a gas, a process known as sublimation. This accounts for effects like the dry ice sublimating at standard pressure and the routine defrosting of a freezer.
A chemistry student mixes 5 grams of sodium chloride (NaCl) in 100 ml of water and stirs until all of the salt is dissolved. Once dissolved, the student measures the electrical conductivity of the solution. An additional 5 grams of NaCl is then dissolved in the solution. Which statement MOST accurately describes how the additional five grams of salt will affect the electrical conductivity of the solution? A) The conductivity of the solution will increase because more ions are being added to the solution. B) The conductivity of the solution will decrease because salt is an insulator and more is being added. C) The conductivity of the solution will decrease because the concentration has changed--the solution is more dense. D) The conductivity of the solution will increase because additional electrical potential is being added to the solution.
Low-frequency red light is used in dark rooms because it does not expose the film. This is because the red light has a low
energy. It will not disrupt the picture developing process by overexposing too much light on the film.
The answer is B (energy). I have had this question before and B is correct.
A 49 N box is to be pulled up a 10 degree ramp at an angle of 40 degrees to the ramp that is 5 m long. The box starts at the base of the ramp. Of the coef of Kinetic friction is 0.1, how hard do you have to pull to make the box to move up the ramp at a constant velocity?
Answer:
17.4 N
Explanation:
According to Newton's second law, the net force acting on the box along the ramp is equal to the product of mass and acceleration:
[tex]F_{net}=ma[/tex]
If we want to move the box at constant velocity, this means acceleration equal to zero: a = 0, so the previous equation becomes:
[tex]F_{net}=0[/tex] (1)
Let's now understand what are the forces exerted on the box along the surface of the ramp:
- The pull (the applied force), let's call it F, which pulls up along the ramp. However, this pull is applied at an angle of 40 degrees, so the actual pull along the ramp will be [tex]F cos 40^{\circ}[/tex]
- The component of the weight parallel to the surface of the ramp, equal to
[tex]-mg sin \theta[/tex]
where (mg) = 49 N is the weight of the box and [tex]\theta=10^{\circ}[/tex] is the angle of the ramp. This force pulls down along the ramp, so we put a negative sign in front of it.
- The frictional force, equals to
[tex]-\mu mg cos \theta[/tex]
where [tex]\mu=0.1[/tex] is the coefficient of friction. This force pulls down along the ramp (in the opposite direction of the motion), so we put a negative sign as well
Therefore, the equation for the net force (1) becomes:
[tex]F cos 40^{\circ}-mg sin \theta -\mu mg cos \theta =0[/tex]
from which we can find the value of F:
[tex]F=\frac{mg sin \theta + \mu mg cos \theta}{cos 40^{\circ}}=\frac{(49 N)(sin 10^{\circ})+(0.1)(49 N)(cos 10^{\circ})}{cos 40^{\circ}}=17.4 N[/tex]
defonition of quarks
Quarks are fundamental particles that make up other subatomic particles such as protons and neutrons. Quarks are not made up of any other particles.
A crane lifts up two boxes.
Which free body diagram shows the forces acting on block A?
Answer:
The 3rd graph
Explanation:
A free body diagram is a diagram which shows all the forces acting on an object.
The problem asks us to find the free body diagram of block A, so we must find all the forces acting on block A.
We have 3 forces acting on block A in total:
- The force of gravity (its weight), which pushes the block downward (in the diagram, it is the force represented with [tex]F_{gA}[/tex]
- The tension in the rope 1, which pulls block A upwards: this force is represented with [tex]F_{T1}[/tex]
- The tension in the rope 2, due to the weight of block 2, which pulls block A downwards: this force is represented with [tex]F_{T2}[/tex]
Based on the direction of these 3 forces, the correct diagram is the 3rd one.
Answer:
t he third graph
Explanation:
a 10 kg animal is running at a rate of 3.0 m/s. What is the kinetic energy of the animal?
Answer:
The kinetic energy of the animal is 45 Joule.
Explanation:
Kinetic energy of the animal is given by,
Kinetic energy = [tex]\frac{1}{2} m v^{2}[/tex]
Given: m = 10 kg , v = 3 m/s
Thus,
Kinetic energy = [tex]\frac{1}{2} (10) (3)^{2}[/tex]
Kinetic energy = 45 Joule,
The kinetic energy of the animal is 45 Joule.
Four techniques used in propaganda advertising are generalization, scare tactic, exaggeration, and .
and bandwagon is another technique
Why is the direction of position V upwards?
Answer:
The wave is moving from left to right (as indicated by the arrow), so, given that at the current instance the amplitude of the position V is 0 (or whatever midpoint the dashed line corresponds to), in the immediately next instance the position will continue increasing as the wave moves from left to right. The peak currently shown at U will at some point "arrive" at V. At that point the location V will have the maximum amplitude. After that the direction at position will be downward, etc.
A 67kg stove is located on the 70th floor of a building (230m above ground). The stove has _______ energy. Calculate it.
Answer:
Potential energy , because it is defined as the energy held by object because of its position relative to other objects.. It is based on its distance from ground
Given data
mass (m) = 67 kg ,
height (h) = 230 m ,
Potential energy (P.E.) = m. g. h
= 67 × 9.81 × 230
= 151172.1 J
P.E. = 151.18 KJ
What are ph levels? Why are they important? What’s there acceptable level/condition?
pH measures the acidity or alkalinity of a substance, with 7 being neutral.
The term pH is a measure of how acidic or alkaline (basic) a substance is. The pH scale is logarithmic and ranges from 0 to 14, where 7 is considered neutral. A pH below 7 indicates acidity, while a pH above 7 indicates alkalinity. The acceptable level of pH varies depending on the substance and the biological system. For example, in humans, the normal range of blood pH is between 7.35 and 7.45, which is slightly alkaline. Conditions such as acidosis and alkalosis occur when the blood pH falls too low or rises too high, respectively.
Maintaining a consistent pH is crucial in living organisms to ensure optimal conditions for chemical reactions. Even small fluctuations in pH levels can affect protein structure and function, which is critical for life processes. Outside of biological systems, pH levels are also significant in environmental contexts, such as the impact of Acid Rain on the pH of natural waters, which is important for the survival of aquatic life.
PLZ HELP, BRAINLIEST !!
The denser a liquid, the slower it flows. The table below shows the mass and volume of two different liquids.
Comparison of Liquids
Liquid Mass (g) Volume
(cm3)
A 18 10
B 8 20
Which of the two liquids flows slower?
Liquid A flows slower.
Liquid B flows slower.
Both liquids flow equally.
This cannot be determined.
Answer: liquid A flows slower i got it right on the exam
Explanation:
Which statement about he diagram is accurate
A. the forces pointing up and down are unbalanced.
B. The forces pointing in and down are balanced
C.The forces pointing right and left are balanced
D.There is a net force of 200 N to the left
B) The forces pointing in and down are balanced
300n on the top and 300n on the bottom results in it being balanced
In the given diagram, the forces pointing up and down are balanced since they are equal in magnitudes and will cancel each other in magnitude.
What is force?Force acting on an object is able to deform it or to change its state of motion or rest. Force is a vector quantity and is characterised by its magnitude and direction.
When two same or different forces are acting in the same direction on an object, the resultant force will be the sum of magnitude of the two forces. If two forces are acting in the opposite directions, they will cancel each other in magnitudes.
In the given diagram, the force acting up and down are equal thus, they will cancel each other and is said to be balanced. The net force to the right direction is 200 N since 200 from 400 N is cancelled by the force with 200 N leftwards. Hence, option b is correct.
To find more on force, refer here:
https://brainly.com/question/26115859
#SPJ5
Which of the vectors below is the sum of vectors a and B, shown here?
(NEED ANSWER ASAP 55 Points)
B looks closest ...
move tail of down pointing vector to tail of other one and make a parallelogram ... join junctions of first tails to final arrowheads ...
Or
join tail of right hand vector to tip of left hand vector to get two sides of a vector triangle.
then join tail of left hand vector to tip of right vector for third side of triangle and the resultant.
either way should work, both give same answer
Vector 'a' is made out of some 'up' and some 'right'.
Vector 'b' cancels most or all of the 'up' part of 'a', leaving only the 'right' part and maybe a slight bit of 'up'.
The only choice that is mostly 'right' with maybe a slight bit of 'up' is choice-B.
Choice-A has too much 'up' in it.
Choices C and D both have some 'left' in them. They couldn't get any 'left' from 'a' or 'b'.
which of the following is not necessary in a great summary?your investigayltion, your predicatio, excuses, possible errors?
Excuse are not acceptable
While traveling, John let destination A at 9 am. Driving until 7 pm, he travelled a total of 500 miles. The next day, John left at 9 am and drove until 5 pm, covering 270 miles. What was the average speed for both days, while driving
18 hours 770
770/18 average speed.
Answer:
The average speed for both days, while driving is 42.77 miles/hr.
Explanation:
Given that,
Distance first day = 500 miles
Distance second day = 270 miles
According to question,
The distance covered by the john in 10 hours = 500 miles
Next day ,
The distance covered by the john in 8 hours = 270 miles
We need to calculate the average speed for both days
Using formula of the average speed
[tex]v_{avg}=\dfrac{D}{T}[/tex]
Where, D = total distance
T = total time
Put the value into the formula
[tex]v_{avg}=\dfrac{500+270}{10+8}[/tex]
[tex]v_{avg}=\dfrac{770}{18}[/tex]
[tex]v_{avg}=42.77\ miles/hr[/tex]
Hence, The average speed for both days, while driving is 42.77 miles/hr.
You input 75 J of work with a wedge. If the wedge does 65 J of useful work, what if the efficiency of the wedge ?
Answer:
Efficiency of wedge is the ratio of "work done by the machine to the work supplied to the machine".
Efficiency (η) = Work done by machine ÷ Work supplied
= 65 ÷ 75
= 0.86%
Efficiency of wedge is 86%
Which of the following statements apply to electric charges? please help this is the only question i need done!!
A. There are three types of charges.
B. Like charges attract, opposite charges repel.
C. If a positively charged rod is brought close to a positively charged object, the two objects will repel.
D. If a negatively charged rod is brought close to a positively charged object, the two objects will repel.
The only correct statement on that list is choice-C: If a positively charged rod is brought close to a positively charged object, the two objects will repel.
Answer:
C. If a positively charged rod is brought close to a positively charged object, the two objects will repel.
Explanation:
According to coulomb's law, the magnitude of the electric force between two point charges at rest is directly proportional to the product of the magnitude of both charges and inversely proportional to the square of the distance that separates them. This force is repulsive for like charges and attractive for opposite charges.