Question 1

The plot below shows the position of an object as a function of time.The letters H-L represent particular moments of time.At which moment in time is the speed of the object the highest? 
A)J
B)H
C)I
D)K
E)L

Accepted Answer

The answer of The plot below shows the position of...

Question 2

Two identical stones are dropped from a tall building,one after the other.Assume air resistance is negligible.While both stones are falling,what will happen to the vertical distance between them?
A)It will increase.
B)It will decrease.
C)It will remain the same.
D)It will first increase and then remain constant.

Accepted Answer

Since both stones are in free fall and the second stone is dropped after the first, the first stone will have a head start and will always be moving faster than the second stone. Therefore, the vertical distance between them will increase over time.

Question 3

The motions of a car and a truck along a straight road are represented by the velocity-time graphs below.The two vehicles are initially alongside each other at time t = 0.  At time T,what is true of the distances traveled by the vehicles since time t = 0?
A)They will have traveled the same distance.
B)The truck will not have moved.
C)The car will have traveled farther than the truck.
D)The truck will have traveled farther than the car.

Accepted Answer

The answer of The motions of a car and a...

Question 4

Which of the following situations is impossible?
A)An object has velocity directed east and acceleration directed west.
B)An object has velocity directed east and acceleration directed east.
C)An object has zero velocity but non-zero acceleration.
D)An object has constant non-zero acceleration and changing velocity.
E)An object has constant non-zero velocity and changing acceleration.

Accepted Answer

An object cannot have a constant non-zero velocity if its acceleration is changing. Acceleration is the rate of change of velocity, so if acceleration changes, velocity must also change.

Question 5

It is possible to have a negative average velocity,depending on the choice of coordinate system.Is it possible for an object to have a negative average speed?

Accepted Answer

The answer of It is possible to have a negative...

Question 6

A racing car accelerates uniformly from rest along a straight track.This track has markers spaced at equal distances along it from the start,as shown below.The car reaches a speed of 140 km/h as it passes marker 2.  Whereabouts on the track was the car when it was travelling at half this speed,i.e.at 70 km/h?
A)before marker 1
B)at marker 1
C)between marker 1 and marker 2

Accepted Answer

The answer of A racing car accelerates uniformly from rest...

Question 7

An object is dropped from rest into a pit,and accelerates due to gravity at roughly 10 m/s2.It hits the ground in 5 seconds.A rock is then dropped from rest into a second pit,and hits the ground in 10 seconds.How much deeper is the second pit,compared to the first pit? Neglect air resistance.
A)four times deeper
B)two times deeper
C)three times deeper
D)five times deeper

Accepted Answer

The depth of a pit is determined by the formula $ d = \frac{1}{2}gt^2 $. For the first pit, $ d_1 = \frac{1}{2} \times 10 \times 5^2 = 125 $ meters. For the second pit, $ d_2 = \frac{1}{2} \times 10 \times 10^2 = 500 $ meters. The second pit is $ \frac{500}{125} = 4 $ times deeper than the first pit.

Question 8

A skier begins skiing straight down a hill having a constant slope,starting from rest.If friction is negligible,as the skier goes down the hill,his/her
A)acceleration is constant,with a value less than 10 m/s/s.
B)acceleration is constant,with a value of roughly 10 m/s/s.
C)acceleration increases with time.
D)acceleration is zero.

Accepted Answer

The acceleration of the skier is constant and equal to the component of gravitational acceleration along the slope, which is less than 10 m/s².

Question 9

Two identical objects A and B fall from rest from different heights to the ground.If object B takes twice as long as A to reach the ground,what is the ratio of the heights from which A and B fell? Neglect air resistance.
A)1 : 
B)1 : 2
C)1 : 4
D)1 : 8

Accepted Answer

Let the height of object A be h.
Then, the time taken by object A to reach the ground is given by:
t = sqrt(2h/g)
where g is the acceleration due to gravity.

For object B, the height is 4h (since it falls for twice the time).
So, the time taken by object B is given by:
2t = sqrt(8h/g)

Equating the above two equations and solving for h, we get:
h = 4h/2^2
=> h = h/4

Therefore, the ratio of the heights from which A and B fell is h:(4h) = 1:4.

Question 10

A stone is thrown vertically upwards,reaches a highest point,and returns to the ground.When the stone is at the top of its path,its acceleration
A)is zero.
B)is directed upwards.
C)is directed downwards.
D)changes direction from upwards to downwards.

Accepted Answer

At the highest point, the stone's velocity is zero, but the acceleration due to gravity is still acting downwards at 9.8 m/s².

Question 11

A child standing on a bridge throws a rock straight down.The rock leaves the child's hand at t = 0.Which of the graphs shown here best represents the velocity of the stone as a function of time?
A)

B)

C)

D)

E)

Accepted Answer

The answer of A child standing on a bridge throws...

Question 12

The plot below shows the position of an object as a function of time.The letters H-L represent particular moments of time.At which moment in time is the speed of the object equal to zero? 
A)I
B)H
C)J
D)K
E)L

Accepted Answer

The answer of The plot below shows the position of...

Question 13

A ball is thrown vertically upward and then comes back down.During the ball's flight up and down,its velocity and acceleration vectors are
A)always in opposite directions.
B)always in the same direction.
C)first in opposite directions and then in the same direction.
D)first in the same direction and then in opposite directions.

Accepted Answer

When the ball is thrown upward, its velocity is upward while acceleration due to gravity is downward, making them opposite. As the ball comes down, both velocity and acceleration are downward, making them in the same direction.

Question 14

A person in a car is driving down a straight road.The instantaneous acceleration is decreasing with time,but is directed in the direction of the car's motion.The speed of the car is
A)increasing with time.
B)decreasing with time.
C)constant.

Accepted Answer

The car's acceleration is in the direction of its motion, meaning it is speeding up. Although the acceleration is decreasing, it is still positive, so the speed continues to increase.

Quiz 2: Motion in One Dimension

The plot below shows the position of an object as a function of time.The letters H-L represent particular moments of time.At which moment in time is the speed of the object the highest?

Two identical stones are dropped from a tall building,one after the other.Assume air resistance is negligible.While both stones are falling,what will happen to the vertical distance between them?

The motions of a car and a truck along a straight road are represented by the velocity-time graphs below.The two vehicles are initially alongside each other at time t = 0. At time T,what is true of the distances traveled by the vehicles since time t = 0?

Which of the following situations is impossible?

It is possible to have a negative average velocity,depending on the choice of coordinate system.Is it possible for an object to have a negative average speed?

An object is dropped from rest into a pit,and accelerates due to gravity at roughly 10 m/s2.It hits the ground in 5 seconds.A rock is then dropped from rest into a second pit,and hits the ground in 10 seconds.How much deeper is the second pit,compared to the first pit? Neglect air resistance.

A skier begins skiing straight down a hill having a constant slope,starting from rest.If friction is negligible,as the skier goes down the hill,his/her

Two identical objects A and B fall from rest from different heights to the ground.If object B takes twice as long as A to reach the ground,what is the ratio of the heights from which A and B fell? Neglect air resistance.

A stone is thrown vertically upwards,reaches a highest point,and returns to the ground.When the stone is at the top of its path,its acceleration

A child standing on a bridge throws a rock straight down.The rock leaves the child's hand at t = 0.Which of the graphs shown here best represents the velocity of the stone as a function of time?

The plot below shows the position of an object as a function of time.The letters H-L represent particular moments of time.At which moment in time is the speed of the object equal to zero?

A ball is thrown vertically upward and then comes back down.During the ball's flight up and down,its velocity and acceleration vectors are

A person in a car is driving down a straight road.The instantaneous acceleration is decreasing with time,but is directed in the direction of the car's motion.The speed of the car is