Question 1

The vertical height attained by a basketball player who achieves a hang time of a full 1 s is about
A)0.8 m.
B)1 m.
C)1.2 m.
D)2.5 m.
E)more than 2.5 m.

Accepted Answer

The formula for maximum height h attained by a projectile with initial velocity v and hang time t is given by:
h = vt - (1/2)gt^2
where g is the acceleration due to gravity (9.8 m/s^2)
Substituting v = 0 (since the player has no initial vertical velocity), and t = 1 s, we get:
h = (1/2)g(1 s)^2 = 4.9 m/s^2
Therefore, the vertical height attained by the basketball player is approximately 1.2 m. Therefore, the best choice is C).

Question 2

Six seconds after starting from rest,a freely-falling baseball has a speed of
A)10 m/s.
B)30 m/s.
C)60 m/s.
D)70 m/s.

Accepted Answer

The acceleration due to gravity is approximately 9.8 m/s^2. After falling for 6 seconds, the velocity of the ball can be found using the equation:
v = at, where v is the final velocity, a is the acceleration due to gravity, and t is the time.
Thus, v = (9.8 m/s^2)(6 s) = 58.8 m/s. Rounding to the nearest whole number, the answer is 60 m/s, which is choice C.

Question 3

The acceleration of a cart rolling down an inclined plane (a ramp)
A)is approximately constant.
B)increases with time.
C)decreases with time.

Accepted Answer

The acceleration of a cart rolling down an inclined plane is approximately constant, as long as there is no air resistance, friction, or other external forces acting on it. This is because the force of gravity causes a constant acceleration downwards, which is independent of the mass of the cart. However, if there is friction or other external forces, the acceleration may not be constant but may decrease over time.

Question 4

If a freely-falling object were somehow equipped with a speedometer,its speed reading would increase each second by about
A)5 m/s.
B)10 m/s.
C)15 m/s.
D)a variable amount.

Accepted Answer

Objects in freefall experience a constant acceleration due to gravity of approximately 9.8 m/s². This means that the object's speed increases by 9.8 m/s every second. However, due to air resistance and other factors, the acceleration may not be exactly 9.8 m/s². But on average, the speed reading should increase by approximately 10 m/s each second.

Question 5

On the surface of the Moon where acceleration due to gravity is less,a person's hang time would be
A)longer.
B)shorter.
C)the same as on Earth.

Accepted Answer

The hang time of a person is the duration for which they remain in the air after jumping. Hang time is dependent on the acceleration due to gravity, which is weaker on the Moon than on Earth. Therefore, the person's hang time would be longer on the Moon as compared to Earth.

Question 6

Phil Physiker standing at the edge of a cliff throws one ball straight up and another ball straight down,both with the same speed.Both balls hit the ground at
A)different speeds.
B)the same speed in the same time.
C)the same speed in different times.
D)none of the above

Accepted Answer

The balls hit the ground at the same speed because their initial speeds are equal and acceleration due to gravity affects them equally, but they reach the ground at different times due to their initial directions of motion.

Question 7

The acceleration of a vertically-thrown ball at the top of its path is A)zero. B)10 m/s². C)between zero and 10 m/s². D)dependent on the mass of the ball.

Accepted Answer

The acceleration of a vertically-thrown ball at the top of its path is still 9.8 m/s^2 (approximately 10 m/s^2) downwards, due to gravity. The velocity of the ball at the top of its path is zero, but acceleration due to gravity remains constant regardless of the ball's position or velocity.

Question 8

If you toss a ball straight upward at 40 m/s with no air resistance,one second before it reaches the top of its path its speed is
A)zero.
B)10 m/s.
C)20 m/s.
D)30 m/s
E)40 m/s.

Accepted Answer

The acceleration due to gravity is approximately 9.8 m/s^2 downward. If you toss a ball upward at 40 m/s, it will decelerate at this rate. One second before reaching the top, its speed would have decreased by 9.8 m/s from whatever speed it had 1 second earlier. At the very top of its path, its speed is 0 m/s (since it momentarily stops before falling back down). Therefore, one second before reaching the top, its speed would be 9.8 m/s, which is approximately 10 m/s when rounded to the nearest ten, making option B the closest answer.

Question 9

If a freely-falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s²,then its speed reading would increase each second by A)10 m/s. B)20 m/s. C)30 m/s. D)40 m/s. E)depends on its initial speed

Accepted Answer

The acceleration due to gravity is 20 m/s^2. This means that the object will increase its speed by 20 m/s every second it falls. Therefore, the speedometer reading will increase by 20 m/s every second, making choice B the correct answer.

Question 10

At the end of 2 seconds an apple freely falling from rest has a speed of
A)1 m/s.
B)5 m/s.
C)10 m/s.
D)more than 10 m/s.

Accepted Answer

The speed of a freely falling object from rest under gravity is given by the formula v = gt, where g is the acceleration due to gravity (approximately 9.8 m/s²) and t is the time in seconds. After 2 seconds, v = 9.8 m/s² * 2 s = 19.6 m/s, which is more than 10 m/s.

Question 11

An object travels 8 m in the 1st second of travel,8 m again during the 2nd second of travel,and 8 m again during the 3rd second.Its acceleration is A)0 m/s². B)5 m/s². C)8 m/s². D)10 m/s². E)more than 10 m/s².

Accepted Answer

Acceleration is the change in velocity per unit time. Since the object travels the same distance of 8 m in each second of travel, its velocity does not change, and therefore its acceleration is 0.

Question 12

If you toss a ball straight upward at 40 m/s,with no air resistance it returns to you at a speed of
A)zero.
B)10 m/s.
C)40 m/s.
D)more than 40 m/s.

Accepted Answer

In the absence of air resistance, the ball will return at the same speed it was thrown upwards due to the conservation of energy. The only forces acting on the ball are gravity and the initial force that threw it upwards. Gravity slows the ball down on its way up and speeds it up at the same rate on its way down, so it returns at the initial speed of 40 m/s.

Question 13

The speed of a vertically-thrown ball at the top of its path is A)zero. B)10 m/s². C)between zero and 10 m/s². D)dependent on the mass of the ball.

Accepted Answer

At the top of its path, the ball comes to a momentary stop before it starts to fall back down due to gravity. Therefore, the velocity of the ball at the top is zero. The mass of the ball does not affect this velocity.

Question 14

Ten seconds after starting from rest,a freely-falling baseball will have a speed of about
A)10 m/s.
B)50 m/s.
C)100 m/s.
D)500 m/s.
E)more than 500 m/s.

Accepted Answer

A freely-falling object near the Earth's surface accelerates at approximately 9.8 m/s². After 10 seconds, its speed will be 9.8 m/s² * 10 s = 98 m/s, which is approximately 100 m/s.

Question 15

A freely-falling object has a speed of 30 m/s at one instant.Exactly 2 seconds later its speed will be
A)the same.
B)40 m/s.
C)50 m/s.
D)more than 50 m/s.

Accepted Answer

A freely-falling object accelerates at approximately 9.8 m/s² due to gravity. After 2 seconds, its speed increases by 2 * 9.8 m/s = 19.6 m/s, making the new speed approximately 30 m/s + 19.6 m/s = 49.6 m/s, which rounds to 50 m/s.

Question 16

If you toss a ball straight upward at 40 m/s with no air resistance,6 seconds later its speed is
A)zero.
B)10 m/s.
C)20 m/s.
D)30 m/s
E)40 m/s.

Accepted Answer

The answer of If you toss a ball straight upward...

Question 17

What is the acceleration of a scooter that maintains a constant velocity of 15 m/s for 10 s? A)0 m/s² B)0.15 m/s² C)1.5 m/s² D)15 m/s²

Accepted Answer

Acceleration is defined as the rate of change of velocity. If the velocity is constant, there is no change in velocity, and thus, there is no acceleration. Therefore, the acceleration of the scooter is 0 m/s². The correct answer is A.

Question 18

An object in free fall has a speed of 60 m/s.One second later its speed is
A)10 m/s.
B)30 m/s.
C)60 m/s.
D)70 m/s.

Accepted Answer

In free fall, an object experiences a constant acceleration due to gravity, which is approximately 9.8 m/s^2 near the Earth's surface. Therefore, after one second, the object's speed would increase by 9.8 m/s.

60 m/s + 9.8 m/s = 69.8 m/s

Rounding to the nearest whole number, the object's speed one second later would be 70 m/s. Therefore, the correct choice is D.

Question 19

Phil Physiker standing at the edge of a cliff throws one ball straight up and another ball straight down,both with the same speed.Neglecting air resistance,which ball hits the ground below with the greater speed?
A)the one thrown upward
B)the one thrown downward
C)neither,both hit with the same speed

Accepted Answer

Both balls hit the ground with the same speed because, neglecting air resistance, the only force acting on them is gravity, which accelerates both balls at the same rate regardless of their initial motion direction.

Question 20

If you toss a ball straight upward at 40 m/s with no air resistance,one second after it reaches the top of its path its speed is
A)zero.
B)10 m/s.
C)20 m/s.
D)30 m/s
E)40 m/s.

Accepted Answer

When a ball is tossed straight upward, it decelerates due to gravity (approximately 9.8 m/s^2) until it reaches the top of its path, where its velocity is momentarily 0 m/s. After reaching the top, it starts accelerating downwards due to gravity. One second after reaching the top, its speed would be 9.8 m/s, but since the options are in multiples of 10, the closest answer is 10 m/s (B).

Quiz 1: Patterns of Motion and Equilibrium

The vertical height attained by a basketball player who achieves a hang time of a full 1 s is about

Six seconds after starting from rest,a freely-falling baseball has a speed of

The acceleration of a cart rolling down an inclined plane (a ramp)

If a freely-falling object were somehow equipped with a speedometer,its speed reading would increase each second by about

On the surface of the Moon where acceleration due to gravity is less,a person's hang time would be

Phil Physiker standing at the edge of a cliff throws one ball straight up and another ball straight down,both with the same speed.Both balls hit the ground at

The acceleration of a vertically-thrown ball at the top of its path is

If you toss a ball straight upward at 40 m/s with no air resistance,one second before it reaches the top of its path its speed is

If a freely-falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s2,then its speed reading would increase each second by

At the end of 2 seconds an apple freely falling from rest has a speed of

An object travels 8 m in the 1st second of travel,8 m again during the 2nd second of travel,and 8 m again during the 3rd second.Its acceleration is

If you toss a ball straight upward at 40 m/s,with no air resistance it returns to you at a speed of

The speed of a vertically-thrown ball at the top of its path is

Ten seconds after starting from rest,a freely-falling baseball will have a speed of about

A freely-falling object has a speed of 30 m/s at one instant.Exactly 2 seconds later its speed will be

If you toss a ball straight upward at 40 m/s with no air resistance,6 seconds later its speed is

What is the acceleration of a scooter that maintains a constant velocity of 15 m/s for 10 s?

An object in free fall has a speed of 60 m/s.One second later its speed is

Phil Physiker standing at the edge of a cliff throws one ball straight up and another ball straight down,both with the same speed.Neglecting air resistance,which ball hits the ground below with the greater speed?

If you toss a ball straight upward at 40 m/s with no air resistance,one second after it reaches the top of its path its speed is

If a freely-falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s²,then its speed reading would increase each second by