Physics 1210 exam 1

If more horizontal force is applied to a sliding object than is needed to maintain a constant velocity

A) the object accelerates in the direction of the applied force

Suppose that a tiny gun made of a strong but very light material fires a bullet that is more massive than the gun itself. For such a weapon

A) the target would be safer than the shooter.

A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is

A) zero.

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

B) 20 m/s.

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

B) 6 km/h/s.

Which of the following has the largest momentum relative to the Earth's surface?

B) a pickup truck speeding along a highway

Your car is coasting on level ground at 60 km/h and you apply the brakes until the car slows to 40 km/h. If you suddenly release the brakes now, the car tends to

B) continue moving at 40 km/h

Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to

B) follow a straight-line path.

A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the

B) force the glove exerts on the ball.

Your weight is

B) the gravitational attraction force between you and the Earth.

Compared to the mass of a certain object on Earth, the mass of the same object on the moon is

B) the same.

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

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

If the mass of an object does not change, a constant net force on the object produces constant

B)acceleration

When you stand at rest on a pair of bathroom scales, the readings on the scales will always

C. add up to equal your weight.

Whereas Aristotle relied on logic in explaining nature, Galileo relied on

C. experiment

If a car accelerates from rest at 2 meters per second per second, its speed 3 seconds later will be about

D) 6 m/s.

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much

D) all of these

Which has zero acceleration? An object

D) all of these

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

D) increasing.

For an action force, there must be a reaction force that

D) is exactly equal in magnitude.

Galileo's use of inclined planes allowed him to effectively

A) slow down the acceleration of free fall.

A 10-N falling object encounters 10 N of air resistance. The net force on the object is

A) 0 N

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

A) 0.

If a projectile is fired straight up at a speed of 10 m/s, the time it takes to reach the top of its path is about

A) 1 second.

A ball is thrown upwards. Neglecting air resistance, what initial upward speed does the ball need to remain in the air for a total time of 10 seconds?

A) about 50 m/s

When you are in the way of a fast-moving object and can't get out of its way, you will suffer a smaller force of impact if you decrease its momentum over a

A) long time

In which case would you have the largest mass of gold? If your chunk of gold weighed 1 N on the

A) moon.

Which of the following is a scientific statement?

A. The moon is made of green cheese.

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

B) 10 m/s.

A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is

B) 10 times as much

In science, facts

B. may change

A piece of rope is pulled by two people in a tug-of-war. Each pulls with 400 N of force. What is the tension in the rope?

B.) 400 N

Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration in meters per second per second?

C) 4.0

When a woman stands at rest with both feet on a scale, it reads 500 N. When she gently lifts one foot, the scale reads

C) 500 N.

A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is

C) about 30 m/s.

If an object of constant mass experiences a constant net force, it will have a constant

C) acceleration.

Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war. The greater force on the rope is exerted by

C) both the same, interestingly

The two measurements necessary for calculating average speed are

C) distance and time.

A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is

C) equal to its weight

A kilogram is a measure of an object's

C) mass.

As a ball falls, the action force is the pull of Earth on the ball. The reaction force is the

C) pull of the ball's mass on the Earth

Compared to falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the

C) stopping time is longer on the carpet

The attraction of a person's body toward Earth is called weight. The reaction to this force is

C) the person's body pulling on the Earth

An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be

C) twice as much

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

E) 100 m/s.