Question 1

A ___________ is a body whose only acceleration is the downward acceleration due to gravity.

Accepted Answer

The answer of A ___________ is a body whose only...

Question 2

In a laboratory on Earth, all the air is pumped from a large tube. A feather and a steel ball are simultaneously released from rest inside the tube. What happens next?

Accepted Answer

A)  Both objects float weightless inside the tube. 
B)  The steel ball falls and hits the bottom before the feather. 
C)  The feather falls and hits the bottom before the steel ball. 
D)  Both objects fall and hit the bottom at the same time.

Question 3

Ball A is thrown upward with a velocity of 19.6 m/s. Two seconds later ball B is thrown upward with a velocity of 9.8 m/s. Which ball is first to return to the thrower's hand?

Accepted Answer

A)  A will arrive first. 
B)  A and B will arrive at the same time. 
C)  B will arrive first.

Question 4

To get a clean "swish"-nothing but net-on the basketball floor, you must shoot the ball so that its velocity vector is at least ________ above horizontal when it gets to the hoop.

Accepted Answer

A)  45$\degree$ 
B)  58$\degree$ 
C)  32$\degree$ 
D)  30$\degree$

Question 5

You toss a ball straight up in the air. At the highest point, the ball's

Accepted Answer

A)  velocity and acceleration are zero. 
B)  acceleration is zero but not its velocity. 
C)  velocity is zero and the acceleration is downward. 
D)  velocity is zero and the acceleration is upward.

Question 6

A baseball pitcher throws a fastball at 98 mph. He also has a slower "changeup" pitch, 75 mph, which he throws identically, same windup and same release angle from shoulder height. Which pitch gets to home plate with a flatter trajectory-i.e., velocity vector closer to horizontal?

Accepted Answer

A)  The fastball 
B)  The changeup 
C)  They each have same trajectory, since the distance to home plate is the same.
Fill in the Blank Questions

Question 7

A ball is projected upward with an initial velocity of 10 m/s. It will reach its maximum height in approximately

Accepted Answer

A)  1 s. 
B)  1.5 s. 
C)  2 s. 
D)  2.5 s. 
E)  3 s.

Question 8

A ball is allowed to drop from rest. If the upward direction is positive, then after 2 seconds its velocity will be

Accepted Answer

A)  -19.6 m/s. 
B)  -9.8 m/s. 
C)  9.8 m/s. 
D)  19.6 m/s.

Question 9

Two projectiles are launched 50$\degree$ above horizontal but with different initial speeds. Which of the following must be true while the projectiles are in the air? (Ignore air resistance.)

Accepted Answer

A)  The projectiles will reach the same maximum height. 
B)  The horizontal speeds of both projectiles are the same. 
C)  The horizontal accelerations of both projectiles are the same: zero. 
D)  The one with larger initial speed will experience a larger vertical acceleration.

Question 10

The acceleration due to the Earth's gravity, in English units, is 32 ft/s2. In the absence of air friction, a ball is dropped from rest. Its speed on striking the ground is exactly 132 ft/s. From what height was the ball dropped?

Accepted Answer

A)  165 ft 
B)  272 ft 
C)  132 ft 
D)  421 ft

Question 11

The motion of a falling object is commonly investigated with the aid of a

Accepted Answer

A)  stethoscope. 
B)  microscope. 
C)  kaleidoscope. 
D)  stroboscope.

Question 12

An iron robot falls from rest at a great height. Neglecting air resistance, what is its speed after it has fallen for 3.5 seconds?

Accepted Answer

A)  9.8 m/s 
B)  9.8 m/s2 
C)  13.3 m/s 
D)  34.3 m/s

Question 13

During the first 5 seconds after a ball is dropped from rest, how far will it fall?

Accepted Answer

A)  25 m 
B)  61.3 m 
C)  122.5 m 
D)  245 m 
E)  490 m

Question 14

If you drop a ball in the absence of air resistance, it accelerates downward at 9.8 m/s2. If instead you throw the ball upward, then its downward acceleration after release is

Accepted Answer

A)  less than 9.8 m/s2. 
B)  equal to 9.8 m/s2. 
C)  greater than 9.8 m/s2.

Question 15

A 10 kg object dropped from a certain window strikes the ground in 4.0 s. Neglecting air resistance, a 5 kg object dropped from the same window strikes the ground in

Accepted Answer

A)  1.0 s. 
B)  2.0 s. 
C)  4.0 s. 
D)  8.0 s.

Question 16

After 1 second, a ball dropped from rest will have fallen

Accepted Answer

A)  1.0 m. 
B)  2.45 m. 
C)  4.9 m. 
D)  9.8 m. 
E)  19.6 m.

Question 17

A rifle bullet is fired horizontally at the same instant another bullet is allowed to drop from rest at the same height. Which bullet strikes the earth first?

Accepted Answer

A)  The bullet from the rifle 
B)  The bullet allowed to drop 
C)  Both strike at the same instant.

Question 18

A stone is thrown upward from a bridge at a speed of 10 m/s. It narrowly misses the bridge on the way back down and hits the water at 30 m/s. The bridge is about

Accepted Answer

A)  3 m high. 
B)  20 m high. 
C)  50.5 m high. 
D)  76.5 m high.

Question 19

A body released from rest falls with an acceleration of 9.8 m/s2. If the same body is thrown upward at an angle, and air resistance is negligible, its acceleration after release will be

Accepted Answer

A)  downward and less than 9.8 m/s2. 
B)  downward and equal to 9.8 m/s2. 
C)  downward and greater than 9.8 m/s2. 
D)  upward and equal to 9.8 m/s2. 
E)  upward and greater than 9.8 m/s2.

Question 20

For identical cannons and identical projectiles and identical initial speeds, but different pointing angles, the maximum distance for its projectile is attained for the cannon which launches at

Accepted Answer

A)  32$\degree$ above horizontal. 
B)  45$\degree$ above horizontal. 
C)  either 32$\degree$ or 58$\degree$ above horizontal. 
D)  zero degrees-a flat trajectory.

Exam 3: Falling Objects and Projectile Motion

A ___________ is a body whose only acceleration is the downward acceleration due to gravity.

In a laboratory on Earth, all the air is pumped from a large tube. A feather and a steel ball are simultaneously released from rest inside the tube. What happens next?

Ball A is thrown upward with a velocity of 19.6 m/s. Two seconds later ball B is thrown upward with a velocity of 9.8 m/s. Which ball is first to return to the thrower's hand?

To get a clean "swish"-nothing but net-on the basketball floor, you must shoot the ball so that its velocity vector is at least ________ above horizontal when it gets to the hoop.

You toss a ball straight up in the air. At the highest point, the ball's

A baseball pitcher throws a fastball at 98 mph. He also has a slower "changeup" pitch, 75 mph, which he throws identically, same windup and same release angle from shoulder height. Which pitch gets to home plate with a flatter trajectory-i.e., velocity vector closer to horizontal?

A ball is projected upward with an initial velocity of 10 m/s. It will reach its maximum height in approximately

A ball is allowed to drop from rest. If the upward direction is positive, then after 2 seconds its velocity will be

Two projectiles are launched 50 $\degree$ above horizontal but with different initial speeds. Which of the following must be true while the projectiles are in the air? (Ignore air resistance.)

The acceleration due to the Earth's gravity, in English units, is 32 ft/s². In the absence of air friction, a ball is dropped from rest. Its speed on striking the ground is exactly 132 ft/s. From what height was the ball dropped?

The motion of a falling object is commonly investigated with the aid of a

An iron robot falls from rest at a great height. Neglecting air resistance, what is its speed after it has fallen for 3.5 seconds?

During the first 5 seconds after a ball is dropped from rest, how far will it fall?

If you drop a ball in the absence of air resistance, it accelerates downward at 9.8 m/s². If instead you throw the ball upward, then its downward acceleration after release is

A 10 kg object dropped from a certain window strikes the ground in 4.0 s. Neglecting air resistance, a 5 kg object dropped from the same window strikes the ground in

After 1 second, a ball dropped from rest will have fallen

A rifle bullet is fired horizontally at the same instant another bullet is allowed to drop from rest at the same height. Which bullet strikes the earth first?

A stone is thrown upward from a bridge at a speed of 10 m/s. It narrowly misses the bridge on the way back down and hits the water at 30 m/s. The bridge is about

A body released from rest falls with an acceleration of 9.8 m/s². If the same body is thrown upward at an angle, and air resistance is negligible, its acceleration after release will be

For identical cannons and identical projectiles and identical initial speeds, but different pointing angles, the maximum distance for its projectile is attained for the cannon which launches at

Exam 3: Falling Objects and Projectile Motion

A ___________ is a body whose only acceleration is the downward acceleration due to gravity.

In a laboratory on Earth, all the air is pumped from a large tube. A feather and a steel ball are simultaneously released from rest inside the tube. What happens next?

Ball A is thrown upward with a velocity of 19.6 m/s. Two seconds later ball B is thrown upward with a velocity of 9.8 m/s. Which ball is first to return to the thrower's hand?

To get a clean "swish"-nothing but net-on the basketball floor, you must shoot the ball so that its velocity vector is at least ________ above horizontal when it gets to the hoop.

You toss a ball straight up in the air. At the highest point, the ball's

A baseball pitcher throws a fastball at 98 mph. He also has a slower "changeup" pitch, 75 mph, which he throws identically, same windup and same release angle from shoulder height. Which pitch gets to home plate with a flatter trajectory-i.e., velocity vector closer to horizontal?

A ball is projected upward with an initial velocity of 10 m/s. It will reach its maximum height in approximately

A ball is allowed to drop from rest. If the upward direction is positive, then after 2 seconds its velocity will be

Two projectiles are launched 50 °\degree° above horizontal but with different initial speeds. Which of the following must be true while the projectiles are in the air? (Ignore air resistance.)

The acceleration due to the Earth's gravity, in English units, is 32 ft/s2. In the absence of air friction, a ball is dropped from rest. Its speed on striking the ground is exactly 132 ft/s. From what height was the ball dropped?

The motion of a falling object is commonly investigated with the aid of a

An iron robot falls from rest at a great height. Neglecting air resistance, what is its speed after it has fallen for 3.5 seconds?

During the first 5 seconds after a ball is dropped from rest, how far will it fall?

If you drop a ball in the absence of air resistance, it accelerates downward at 9.8 m/s2. If instead you throw the ball upward, then its downward acceleration after release is

A 10 kg object dropped from a certain window strikes the ground in 4.0 s. Neglecting air resistance, a 5 kg object dropped from the same window strikes the ground in

After 1 second, a ball dropped from rest will have fallen

A rifle bullet is fired horizontally at the same instant another bullet is allowed to drop from rest at the same height. Which bullet strikes the earth first?

A stone is thrown upward from a bridge at a speed of 10 m/s. It narrowly misses the bridge on the way back down and hits the water at 30 m/s. The bridge is about

A body released from rest falls with an acceleration of 9.8 m/s2. If the same body is thrown upward at an angle, and air resistance is negligible, its acceleration after release will be

For identical cannons and identical projectiles and identical initial speeds, but different pointing angles, the maximum distance for its projectile is attained for the cannon which launches at

Two projectiles are launched 50 $\degree$ above horizontal but with different initial speeds. Which of the following must be true while the projectiles are in the air? (Ignore air resistance.)

The acceleration due to the Earth's gravity, in English units, is 32 ft/s². In the absence of air friction, a ball is dropped from rest. Its speed on striking the ground is exactly 132 ft/s. From what height was the ball dropped?

If you drop a ball in the absence of air resistance, it accelerates downward at 9.8 m/s². If instead you throw the ball upward, then its downward acceleration after release is

A body released from rest falls with an acceleration of 9.8 m/s². If the same body is thrown upward at an angle, and air resistance is negligible, its acceleration after release will be