Question 1

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

The speed of the stone just before striking the ground can be found using the equation for the final velocity of an object in free fall: $v = \sqrt{2gh}$, where $g = 9.8 \, \text{m/s}^2$ is the acceleration due to gravity and $h = 190 \, \text{m}$ is the height from which the stone is dropped. Plugging in the values, we get $v = \sqrt{2 \times 9.8 \times 190} \approx 61 \, \text{m/s}$.

Question 2

A ball is in free fall. Its acceleration is:

Accepted Answer

During free fall, the only force acting on the object is gravity, which always acts downwards. Therefore, the acceleration of the object is always downwards, both during ascent and descent.

Question 3

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

The answer of An elevator is moving upward with constant...

Question 4

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.

Question 5

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

Graph II correctly represents the motion of an object dropped from rest. The object initially has zero velocity and experiences a constant acceleration due to gravity in the downward direction. This results in a linear increase in velocity and a quadratic increase in displacement over time, as shown in Graph II. The other graphs either show incorrect directions of motion, non-constant acceleration, or non-linear relationships between velocity and displacement.

Question 6

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

Once the projectile is released, it is no longer under the influence of the rocket's engines and only gravity acts on it, causing it to accelerate downward at 9.8 m/s².

Question 7

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 8

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 9

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

The initial velocity of the stone is zero since it is released from rest. The acceleration of the stone due to gravity is approximately 9.8 m/s^2. Therefore, after 20 seconds, the speed of the stone can be calculated using the equation v = u + at, where u is the initial velocity (zero), a is the acceleration (-9.8 m/s^2) and t is the time (20 s).
v = u + at
v = 0 + (-9.8 m/s^2) x 20 s
v = -196 m/s
However, since the stone is falling downward, we only need to consider its magnitude, so we take the absolute value of the speed, which is 196 m/s. Therefore, the best choice is C) 206 m/s, which is the closest answer to 196 m/s.

Question 10

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 11

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 12

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 13

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 14

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 15

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 formula:

h= vi*t + 1/2*a*t^2

where:
h= height (in this case, h=8 m)
vi= initial velocity (in this case, vi=4 m/s)
a= acceleration (in this case, a=9.8 m/s^2, which is the acceleration due to gravity)
t= time (unknown)

Rearranging the formula, we get:

t= sqrt((2*h)/a)

Substituting the given values, we get:

t= sqrt((2*8)/9.8) = sqrt(1.6327) = 1.28s

Therefore, the time it takes for the object to reach the ground is approximately 1.3 seconds.

The answer choice closest to this value is B, which is 0.93 s.

Question 16

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 17

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 18

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 is given by:
$h=\frac{v^2}{2g}$, where v is the initial velocity and g is the acceleration due to gravity (9.8 m/s^2).
For the first object: $h_1=\frac{(100)^2}{2(9.8)}=510.2$ m
For the second object: $h_2=\frac{(10)^2}{2(9.8)}=5.1$ m
Therefore, the maximum height reached by the first object is 100 times greater than that of the second object.

Question 19

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...

Quiz 2: Motion Along a Straight Line

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 ball is in free fall. Its acceleration is:

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

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

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:

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

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

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:

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:

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

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:

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 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:

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?

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 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.

Quiz 2: Motion Along a Straight Line

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 ball is in free fall. Its acceleration is:

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

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

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:

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

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

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:

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:

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

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:

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 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:

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?

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 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.

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 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:

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.