Physics test 1

Starting from rest, the distance a freely falling object will fall in 0.5 s is about

1.25 m

An apple falls from a tree and hits the ground 5 m below. It hits the ground with a speed of about

10 m/s

Disregarding air drag, how fast must you toss a ball straight up in order for it to take 2 seconds to return to the level from which you tossed it?

10 m/s

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

10 m/s

An object falls freely from rest on a planet where the acceleration due to gravity is 20 meters per second squared. After 5 seconds, the object will have a speed of

100 m/s

An object falls freely from rest on a planet where the acceleration due to gravity is twice as much as it is on Earth. In the first 5 seconds it falls a distance of

250 m

One half second after starting from rest, a freely falling object will have a speed of about

5 m/s

If a car increases its velocity from zero to 60 km/h in 10 seconds, its acceleration is

6 km/h/s

An object is in free fall. At one instant, it travels at a speed of 50 m/s. Exactly 1 s later, its speed is about

60 m/s

A ball thrown horizontally from a point 24 m above the ground, strikes the ground after traveling horizontally a distance of 18 m. With what speed was it thrown?

8.1 m/s

A stone is thrown horizontally at 10 m/s from the edge of a cliff. A stop watch measures the stoneʹs trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff?

91 m

It takes 6 s for a stone to fall to the bottom of a mine shaft. How deep is the shaft?

About 180 m

Suppose that an object is moving with constant acceleration. Make a statement concerning its motion with respect to time.

In equal times its velocity changes by equal amounts

Ignoring air resistance, the horizontal component of a projectileʹs velocity

Remains constant

Suppose that an object is moving with a constant velocity. Make a statement concerning its acceleration.

The acceleration must be equal to zero

A bullet is fired horizontally, and at the same instant a second bullet is dropped from the same height. Ignore air resistance. Compare the times of fall of the two bullets.

They hit at the same time

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

about 1.2 m

Disregarding air resistance, objects fall at constant

acceleration

If an object moves with constant acceleration, its velocity must

change by the same amount each second

If a freely falling object were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be

greater than the second before

If an object falling freely were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be

greater than the second before

In each second of fall, the distance a freely falling object will fall is

increasing

A bullet is fired straight down from the top of a high cliff. Neglecting air resistance, the acceleration of the bullet in meters per second per second

is 9.8

A ball is thrown upward and caught when it comes back down. In the presence of air resistance, the speed with which it is caught is

less than the speed it had when thrown upward

A ball is thrown upwards and caught when it comes back down. In the presence of air resistance, the speed with which it is caught is always

less than the speed it had when thrown upwards

Someone standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greater speed will be

neither -- they will both hit with the same speed

When a rock thrown straight upwards gets to the exact top of its path, its

velocity is zero and its acceleration is about 10 meters per second.

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 in meters per second per second is approximately

zero