Question 1

A ball is in free fall. Its acceleration is:

Accepted Answer

During free fall, the only force acting upon the object is gravity, which is always pointing downwards. Therefore, the acceleration of the ball is also downwards during both ascent and descent.

Question 2

An object is thrown vertically upward with a certain initial velocity in a world where the acceleration due to gravity is 19.6 m/s². The height to which it rises is ____ that to which the object would rise if thrown upward with the same initial velocity on the Earth. Neglect friction.

Accepted Answer

The answer of An object is thrown vertically upward with...

Question 3

A projectile is shot vertically upward with a given initial velocity. It reaches a maximum height of 100 m. If, on a second shot, the initial velocity is doubled then the projectile will reach a maximum height of:

Accepted Answer

The maximum height $h$ reached by a projectile shot vertically upward with initial velocity $v$ is directly proportional to the square of the initial velocity ($v^2$) when air resistance is negligible. Given that the initial shot reaches 100 m, when the initial velocity is doubled, the maximum height will be $4$ times the original height (since $(2v)^2 = 4v^2$). Therefore, the new height will be $4 \times 100\,m = 400\,m$.

Question 4

An object dropped from a window of a tall building hits the ground in 12.0 s. If its acceleration is 9.80 m/s², the height of the window above the ground is:

Accepted Answer

The answer of An object dropped from a window of...

Question 5

A stone is thrown vertically upward with an initial speed of 19.5 m/s. It will rise to a maximum height of:

Accepted Answer

Using the formula for maximum height: 
h = (v^2)/2g

Where: 
v = initial velocity = 19.5 m/s 
g = acceleration due to gravity = 9.8 m/s^2

h = (19.5^2)/(2 x 9.8) = 19.4 m

Therefore, the answer is C) 19.4 m.

Question 6

An elevator is moving upward with constant acceleration. The dashed curve shows the position y of the ceiling of the elevator as a function of the time t. At the instant indicated by the dot, a bolt breaks loose and drops from the ceiling. Which curve best represents the position of the bolt as a function of time?

Accepted Answer

Since the elevator is moving upward with constant acceleration, and the bolt breaks loose from the ceiling, it is only under the influence of gravity. Therefore, the motion of the bolt is that of a freely falling object, which is represented by a parabolic curve. The correct curve should be one that starts at the same height as the dot and has the shape of a parabolic curve. Option B is the only curve that fits this description.

Question 7

One object is thrown vertically upward with an initial velocity of 100 m/s and another object with an initial velocity of 10 m/s. The maximum height reached by the first object will be _______ that of the other.

Accepted Answer

The maximum height reached by an object thrown vertically upward only depends on its initial velocity and the acceleration due to gravity. As both objects experience the same acceleration due to gravity, the maximum height reached by the first object will be directly proportional to its initial velocity. So, the first object will reach a maximum height of 100 times that of the second object. Therefore, the correct answer is B) 100 times.

Question 8

An object is thrown straight down with an initial speed of 4 m/s from a window which is 8 m above the ground. The time it takes the object to reach the ground is:

Accepted Answer

We can use the kinematic equation:
$d = v_i t + \frac{1}{2}at^2$
where $d$ is the distance travelled (8 m in this case), $v_i$ is the initial velocity (-4 m/s, since it's moving downwards), $a$ is the acceleration due to gravity (-9.8 m/s$^2$), and $t$ is the time we're solving for. Plugging in these values, we get:
$8 = -4t + \frac{1}{2}(-9.8)t^2$
Simplifying this equation gives us a quadratic equation:
$4.9t^2 - 4t - 8 = 0$
Using the quadratic formula, we get:
$t = \frac{-(-4) \pm \sqrt{(-4)^2 - 4(4.9)(-8)}}{2(4.9)}$
$t = 0.93$ s (rounded to two decimal places)
Therefore, the time it takes for the object to reach the ground is 0.93 seconds, which corresponds to choice B.

Question 9

An object is thrown vertically into the air. Which of the following five graphs represents the velocity (v) of the object as a function of the time (t)? The positive direction is taken to be upward.

Accepted Answer

The answer of An object is thrown vertically into the...

Question 10

A stone is released from rest from the edge of a building roof 190 m above the ground. Neglecting air resistance, the speed of the stone, just before striking the ground, is:

Accepted Answer

Using the equation  𝑣^2 = 𝑢^2 + 2𝑎𝑠, where 𝑣 = final velocity, 𝑢 = initial velocity (0), 𝑎 = acceleration due to gravity (-9.8 m/s^2), and 𝑠 = displacement (190m):

𝑣^2 = 0^2 + 2(-9.8 m/s^2)(190 m)
𝑣^2 = 3724 m^2/s^2
𝑣 = 61 m/s

Therefore, the speed of the stone just before striking the ground is 61 m/s (option B).

Question 11

A stone is released from a balloon that is descending at a constant speed of 10 m/s. Neglecting air resistance, after 20 s the speed of the stone is:

Accepted Answer

Since the stone is released from a balloon that is descending at a constant speed of 10 m/s, we can consider the initial velocity of the stone to be 0 m/s. Neglecting air resistance, the acceleration of the stone is equal to the acceleration due to gravity, which is approximately 9.8 m/s^2. Therefore, we can use the following equation of motion to find the final velocity of the stone after 20 s:

v = u + at

where
- v is the final velocity
- u is the initial velocity (0 m/s)
- a is the acceleration due to gravity (-9.8 m/s^2 because it is downwards)
- t is the time interval (20 s)

Substituting the given values, we get:

v = 0 + (-9.8 x 20) = -196 m/s

Since the final velocity is downwards, we need to take the absolute value to get the magnitude of the velocity:

|v| = 196 m/s

Therefore, the speed of the stone after 20 s is 196 m/s. The answer is (C).

Question 12

A baseball is hit straight up and is caught by the catcher 2.0 s later. The maximum height of the ball during this interval is:

Accepted Answer

The answer of A baseball is hit straight up and...

Question 13

As a rocket is accelerating vertically upward at 9.8 m/s² near the Earth's surface, it releases a projectile. Immediately after release the acceleration (in m/s²) of the projectile is:

Accepted Answer

The answer of As a rocket is accelerating vertically upward...

Question 14

An object is dropped from rest. Which of the five following graphs correctly represents its motion? The positive direction is taken to be downward.

Accepted Answer

The correct graph should be a straight line with a positive slope, representing constant acceleration due to gravity. Graph II fits this description, as the object's velocity increases linearly with time, corresponding to a constant downwards acceleration. The other graphs show either no motion (Graph I), constant velocity (Graph III), deceleration (Graph IV), or a parabolic curve (Graph V), none of which are consistent with the motion of an object in freefall.

Question 15

A feather, initially at rest, is released in a vacuum 12 m above the surface of the Earth. Which of the following statements is correct?

Accepted Answer

The acceleration of the feather remains constant during the fall due to the acceleration due to gravity, which is approximately 9.8 m/s^2 on the surface of the Earth. In a vacuum, there is no air resistance to alter the acceleration.

Question 16

Neglecting the effect of air resistance a stone dropped off a 175-m high building lands on the ground in:

Accepted Answer

The answer of Neglecting the effect of air resistance a...

Question 17

A stone is dropped from a cliff. The graph (carefully note the axes) that best represents its motion while it falls is:

Accepted Answer

The answer of A stone is dropped from a cliff....

Question 18

An object is released from rest.How far does it fall during the second second of its fall?

Accepted Answer

The answer of An object is released from rest.How far...

Question 19

A heavy ball falls freely, starting from rest. Between the third and fourth second of time it travels a distance of:

Accepted Answer

Assuming the ball is falling vertically under the influence of gravity, we can use the formula for displacement:

d = 1/2 * g * t^2

where d is the displacement, g is the acceleration due to gravity (9.8 m/s^2), and t is the time.

Between the third and fourth second, the time interval is 1 second. Plugging in the values:

d = 1/2 * 9.8 * (4^2 - 3^2) = 34.3 m

Therefore, the ball travels a distance of 34.3 meters between the third and fourth second.

Quiz 2: Motion Along a Straight Line

A ball is in free fall. Its acceleration is:

An object is thrown vertically upward with a certain initial velocity in a world where the acceleration due to gravity is 19.6 m/s². The height to which it rises is ____ that to which the object would rise if thrown upward with the same initial velocity on the Earth. Neglect friction.

A projectile is shot vertically upward with a given initial velocity. It reaches a maximum height of 100 m. If, on a second shot, the initial velocity is doubled then the projectile will reach a maximum height of:

An object dropped from a window of a tall building hits the ground in 12.0 s. If its acceleration is 9.80 m/s², the height of the window above the ground is:

A stone is thrown vertically upward with an initial speed of 19.5 m/s. It will rise to a maximum height of:

One object is thrown vertically upward with an initial velocity of 100 m/s and another object with an initial velocity of 10 m/s. The maximum height reached by the first object will be _______ that of the other.

An object is thrown straight down with an initial speed of 4 m/s from a window which is 8 m above the ground. The time it takes the object to reach the ground is:

An object is thrown vertically into the air. Which of the following five graphs represents the velocity (v) of the object as a function of the time (t) ? The positive direction is taken to be upward.

A stone is released from rest from the edge of a building roof 190 m above the ground. Neglecting air resistance, the speed of the stone, just before striking the ground, is:

A stone is released from a balloon that is descending at a constant speed of 10 m/s. Neglecting air resistance, after 20 s the speed of the stone is:

A baseball is hit straight up and is caught by the catcher 2.0 s later. The maximum height of the ball during this interval is:

As a rocket is accelerating vertically upward at 9.8 m/s² near the Earth's surface, it releases a projectile. Immediately after release the acceleration (in m/s²) of the projectile is:

An object is dropped from rest. Which of the five following graphs correctly represents its motion? The positive direction is taken to be downward.

A feather, initially at rest, is released in a vacuum 12 m above the surface of the Earth. Which of the following statements is correct?

Neglecting the effect of air resistance a stone dropped off a 175-m high building lands on the ground in:

A stone is dropped from a cliff. The graph (carefully note the axes) that best represents its motion while it falls is:

An object is released from rest.How far does it fall during the second second of its fall?

A heavy ball falls freely, starting from rest. Between the third and fourth second of time it travels a distance of:

Quiz 2: Motion Along a Straight Line

A ball is in free fall. Its acceleration is:

An object is thrown vertically upward with a certain initial velocity in a world where the acceleration due to gravity is 19.6 m/s2. The height to which it rises is ____ that to which the object would rise if thrown upward with the same initial velocity on the Earth. Neglect friction.

A projectile is shot vertically upward with a given initial velocity. It reaches a maximum height of 100 m. If, on a second shot, the initial velocity is doubled then the projectile will reach a maximum height of:

An object dropped from a window of a tall building hits the ground in 12.0 s. If its acceleration is 9.80 m/s2, the height of the window above the ground is:

A stone is thrown vertically upward with an initial speed of 19.5 m/s. It will rise to a maximum height of:

One object is thrown vertically upward with an initial velocity of 100 m/s and another object with an initial velocity of 10 m/s. The maximum height reached by the first object will be _______ that of the other.

An object is thrown straight down with an initial speed of 4 m/s from a window which is 8 m above the ground. The time it takes the object to reach the ground is:

An object is thrown vertically into the air. Which of the following five graphs represents the velocity (v) of the object as a function of the time (t) ? The positive direction is taken to be upward.

A stone is released from rest from the edge of a building roof 190 m above the ground. Neglecting air resistance, the speed of the stone, just before striking the ground, is:

A stone is released from a balloon that is descending at a constant speed of 10 m/s. Neglecting air resistance, after 20 s the speed of the stone is:

A baseball is hit straight up and is caught by the catcher 2.0 s later. The maximum height of the ball during this interval is:

As a rocket is accelerating vertically upward at 9.8 m/s2 near the Earth's surface, it releases a projectile. Immediately after release the acceleration (in m/s2) of the projectile is:

An object is dropped from rest. Which of the five following graphs correctly represents its motion? The positive direction is taken to be downward.

A feather, initially at rest, is released in a vacuum 12 m above the surface of the Earth. Which of the following statements is correct?

Neglecting the effect of air resistance a stone dropped off a 175-m high building lands on the ground in:

A stone is dropped from a cliff. The graph (carefully note the axes) that best represents its motion while it falls is:

An object is released from rest.How far does it fall during the second second of its fall?

A heavy ball falls freely, starting from rest. Between the third and fourth second of time it travels a distance of:

An object is thrown vertically upward with a certain initial velocity in a world where the acceleration due to gravity is 19.6 m/s². The height to which it rises is ____ that to which the object would rise if thrown upward with the same initial velocity on the Earth. Neglect friction.

An object dropped from a window of a tall building hits the ground in 12.0 s. If its acceleration is 9.80 m/s², the height of the window above the ground is:

As a rocket is accelerating vertically upward at 9.8 m/s² near the Earth's surface, it releases a projectile. Immediately after release the acceleration (in m/s²) of the projectile is: