Ch3 Practice Test

Neglecting air resistance, a bullet fired straight down from the top of a high cliff has an acceleration of...

10 m/s²

When a ball thrown straight upwards reaches the very top of its path, its acceleration is...

10m/s²

A ball is projected 125m straight upward and then falls the same distance back to its starting point. Neglecting air resistance, its total time in the air is about...

10seconds

If a stone falls to the bottom of a mineshaft in 6 seconds, then the depth of the shaft is about...

180m

When you walk at an average speed of 4 m/s, in 5 s you'll cover a distance of...

20m

An 80km/h airplane flying in the same direction as a 10km/h tail wind has a groundspeed of...

90km/h

A mosquito flying at 3 m/s that encounters a breeze blowing at 3 m/s in the opposite direction has a speed of... a. 0 m/s b. 3 m/s c. 4 m/s d. 6 m/s

a. 0 m/s

An object covers a distance of 8 meters in the first second of travel, another 8 meters during the next second, and 8 meters again during the third second. Its acceleration is... a. 0 m/s² b. 5 m/s² c. 8 m/s² d. 24 m/s²

a. 0 m/s²

A cart changes its speed from 90 m/s to 100 m/s in 10 seconds. During this interval its acceleration is.... a. 1 m/s² b. zero c. 10 m/s² d. none of the above

a. 1 m/s²

A ball is projected 125 meters straight upward and then falls the same distance back to its starting point. Neglecting air resistance, its total time in the air is about... a. 10sec b. 15sec c. more than 20sec d. 5sec

a. 10sec

An object falls freely from rest on a planet where the acceleration due to gravity is twice as much as on Earth. In the first 5 seconds it falls a distance of... a. 250m b. 500m c. 100m d. 150m e. none of the above

a. 250m

A pot that falls from a ledge and hits the ground 45 m below hits the ground at... a. 30 m/s b. 60 m/s c. 120 m/s d. more than 120 m/s

a. 30 m/s

Neglecting air resistance, a ball projected straight upward so it remains in the air for 10 seconds needs an initial speed of... a. 50 m/s b. 60 m/s c. 80 m/s d. 100 m/s e. 110 m/s

a. 50 m/s

The accelerations possible for a ball on an inclined plane... a. range from zero to g b. range from g to infinity c. have no limit

a. range from zero to g

While an iron block near the Earth's surface is in free fall, it undergoes an increase in... a. speed b. acceleration c. both of these d. neither of these

a. speed

While a car travels around a circular track at a constant speed, its...

acceleration is changing as well as the direction

The muzzle velocity of a bullet fired from a new rifle is 100 m/s. Neglecting air resistance, at the end of one second a bullet fired straight up into the air will have traveled a distance of... a. (100+5) m b. (100-5) m c. 100 m d. 5 m e. none of the above

b. (100-5) m

An apple falls from a tree and hits the ground 5 meters below with a speed of about... a. 5 m/s b. 10 m/s c. 15 m/s d. 20 m/s e. not enough info

b. 10 m/s

If you throw a ball straight downward (in the absence of air resistance), after leaving your hand its acceleration is... a. less than 10 m/s² b. 10 m/s² c. greater than 10 m/s²

b. 10 m/s²

The time it takes a car to attain a speed of 30 m/s when accelerating from rest at 2 m/s² is... a. 2sec b. 15sec c. 30sec d. 60sec e. none of the above

b. 15sec

An object at rest near the surface of a distant planet starts to fall freely. If the acceleration there is twice that of the Earth, its speed one second later would be... a. 10 m/s b. 20 m/s c. 30 m/s d. 40 m/s

b. 20 m/s

One half second after starting from rest, a freely falling object will have a speed of about... a. 10 m/s b. 5 m/s c. 20 m/s d. 2 m/s

b. 5 m/s

If a car increases its velocity from zero to 60 m/s in 10 seconds, its acceleration is... a. 3 m/s² b. 6 m/s² c. 60 m/s² d. 600 m/s²

b. 6 m/s²

If an object moves with constant acceleration, its velocity must... a. be constant also b. change by the same amount each second c. change by varying amounts depending on its speed d. always decrease

b. change by the same amount each second

Which of the following is not a vector quantity? a. velocity b. speed c. acceleration d. all are vector quantities e. none are vector quantities

b. speed

A ball is thrown upwards and returns to the same location. Compared with its initial speed its speed when it returns is about... a. half as much b. the same c. twice as much d. four times as much

b. the same

An 80-km/h airplane caught in a 60-km/h crosswind has a resultant speed of... a. 60 km/h b. 80 km/h c. 100 km/h d. 141 km/h

c. 100 km/h

An airplane that flies at 100 km/h in a 100-km/h crosswind has a ground speed of... a. 100 km/h b. 0 km/h c. 141 km/h d. 200 km/h

c. 141 km/h

A humming bird flying at 4 km/h that gets caught in a 3 -km/h crosswind has a resultant speed of about... a. 3 km/h b. 4 km/h c. 5 km/h d. more than 5km/h

c. 5 km/h

A ball starting from rest at the top of an inclined plane accelerates at 2 m/s² and reaches the bottom of the plane in 3 seconds. What is the length of the plane? a. 5m b. 3m c. 9m d. 2m

c. 9m

Katelyn runs along the aisle of a train that moves at 8 m/s. Her speed relative to the floor is 3 m/s. Her speed relative to an observer at rest on the ground is... a. 5 m/s b. 11 m/s c. either depending on her running direction d. none of the above

c. either depending on her running direction

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 downward b. the one thrown upward c. neither, both hit with the same

c. neither, both hit with the same

Phil leans over the edge of a cliff and throws a rock upward at 5 m/s. Neglecting air resistance, two seconds later the rock's speed is... a. zero b. 10 m/s c. 5 m/s d. 15 m/s e. none of the above

d. 15 m/s

When you walk at an average speed of 4 m/s, in 5 s you'll cover a distance of... a. 2m b. 10m c. 15m d. 20m

d. 20m

Neglecting air resistance, how fast must you toss a ball straight up in order for it to take 6 seconds to return to its initial level? a. 5 m/s b. 10 m/s c. 20 m/s d. 30 m/s e. more than 30 m/s

d. 30 m/s

A car's speed 3 seconds after accelerating from rest at 2 m/s² is... a. 2 m/s b. 3 m/s c. 4 m/s d. 6 m/s

d. 6 m/s

A mosquito flying at 3 m/s that encounters a breeze blowing at 3 m/s in the same direction has a speed of... a. 0 m/s b. 3 m/s c. 4 m/s d. 6 m/s

d. 6 m/s

At one instant an object in free fall is moving downward at 50 m/s. One second later its speed is... a. 25 m/s b. 50 m/s c. 55 m/s d. 60 m/s e. 100 m/s

d. 60 m/s

A vehicle undergoes acceleration when it... a. gains speed b. loses speed c. changes its direction d. all of the above

d. all of the above

A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always... a. in the direction of motion b. opposite its velocity c. directed upward d. directed downward e. none of the above

d. directed downward

The distance a freely falling object falls from rest in one -half second is... a. 2m b. 6m c. 4m d. none of the above

d. none of the above

While a car travels around a circular track at a constant speed, its... a. acceleration is zero b. velocity is zero c. inertia is zero d. none of the above

d. none of the above

As water drops fall at a steady rate from leaking faucet they...

get farther apart

Compared with hang time on earth, hang time on the moon would be...

greater

A rock dropped from a 5-m height accelerates at 10 m/s² and strikes the ground 1 s later. If the rock is dropped from a height of 2.5 m, its acceleration of fall is...

the same