PHSC 101 Exam 1: Chapter 1 and 2 Exam

A ball is thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared to its initial speed is

less

A ball thrown straight upward takes 10 s to go up and return to the ground. Because of air resistance, the time taken for the ball just to go up is

less than 5 s

A kilogram is a measure of an object's

mass

A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that

the milk carton has inertia.

An object weighs 30 N on Earth. A second object weighs 30 N on the Moon. Which has the greater mass?

the one on the Moon

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

the person's body pulling on the Earth

If you push a crate across a level floor at constant speed, the friction between the crate and the floor is

the same amount as your pushing force.

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

zero and its acceleration is about 10 m/s/s

When a falling object has reached its terminal velocity, its acceleration is

zero.

Ten seconds after starting from rest, a freely falling object will have a speed of about

100 m/s.

A baseball player bats a ball with a force of 1000 N. The ball exerts a reaction force against the bat of

1000 N

If a freely falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s/s, then its speed reading would increase each second by

20 m/s

A car traveling at 22 m/s comes to an abrupt halt in 0.1 s when it hits a tree. What is the deceleration in meters per second per second of the car?

220

The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is

10 N

An empty roller coaster car at an amusement park takes 3 min to make its ride from start to finish. Neglecting friction, a fully loaded car would take

3 min.

A 500-N parachutist opens his chute and experiences an air resistance force of 800 N. The net force on the parachutist is

300 N upward

A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is

3000N

A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is

400N

An object is pulled northward with a force of 10 N and southward with a force of 15 N. The magnitude of the net force on the object is

5 N

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

5 m/s

A 10-kg block with an initial velocity of 10 m/s slides 10 m across a horizontal surface and comes to rest. It takes the block 2 s to stop. The stopping force acting on the block is about

50 N

The amount of frection that occurs when two material surfaces slide against each other depends on

how much they are pressed together. b. the "stickiness" of atoms on their surfaces. c. both of these -correct

A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. Air resistance just before they hit is actually greater for the

lead-filled ball

A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. The ball to reach the ground first is the

lead-filled ball

A force is a vector quantity because it has both

magnitude and direction

An object maintains its state of motion because it has

mass

Compared with a 1-kg block of solid iron, a 2-kg block of solid iron has the same

mass volume , weight.....(..none of these...correct)

A ball is thrown vertically into the air. Because of air resistance, its time coming down compared to its time going up is

more

The resistive force of friction occurs for

solids. liquids. gases. all of the above CORRECT.

Your weight is

the gravitational attraction between you and the Earth.

As an object freely falls, its

velocity increases

A 100-kg automobile enters a freeway onramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 s. How far does the automobile travel during that time?

300m

The maximum acceleration of a car while towing a second car twice its mass, compared to no towing, is

one-third.

A bullet is dropped from the top of the Empire State Building while another bullet is fired downward from the same location. Neglecting air resistance, acceleration is greatest for the

same for each

Which has the greater mass?

an automobile battery

An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the

arrow's push against the bowstring.

skydiver, who weighs 500 N, reaches terminal velocity of 90 km/h. The air resistance on the diver is then

500 N

A 10-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is

6 N

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

6 km/h/s.

A car accelerates from rest at 2 m/s/s. What is its speed 3 s after the car starts moving?

6 m/s

A player hits a ball with a bat. The action force is the impact of the bat against the ball. The reaction to this force is the

force of the ball against the bat.

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

force the glove exerts on the ball.

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

g

A large and a small person wish to parachute at equal terminal velocities. The larger person will have to

get a larger parachute.

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

10 m/s

The gain in speed each second for a freely falling object is about

10 m/s.

If you drop an object, it will accelerate downward at a rate of about 10 m/s/s. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be

10 m/s/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

10 times as much as the force on the 1-kg book

A 10-N block and a 1-N block lie on a horizontal frictionless table. To push them with equal acceleration, we would have to push with

10 times as much force on the heavier block

A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration in meters per second per second is

0

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

0 N

What is the acceleration of a car that maintains a constant velocity of 100 km/h for 10 s?

0 m/s2

A falling skydiver of mass 100 kg experiences 500-N air resistance. The acceleration of the skydiver is

0.5g

A 1-kg mass at the Earth's surface weighs about

10 N

The average speed of a horse that gallops a distance of 10 km in a time of 30 min is

20 km/h.

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

about 180 m

Which has zero acceleration? An object A) at rest. B) moving at constant velocity. C) in mechanical equilibrium. D) all of these E) none of these

D) all of these

Earth pulls on the Moon. Similarly the Moon pulls on Earth, evidence that

Earth and the Moon are simply pulling on each other.. Earth's and Moon's pulls comprise an action-reaction pair both of these are correct

The scientist to first introduce the concept of inertia was

Galileo

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

Moon

Action and reaction forces comprise the parts of

a single interaction

A skydiver falls toward the Earth. The attraction of Earth on the diver pulls the diver down. What is the reaction to this force?

a. air resistance the diver encounters while falling b. water resistance that will soon act upward on the diver c. the attraction to the planets, stars, and every particle in the universe d. all of these e. none of these- correct

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

about 30 m/s.

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

add to equal your weight.

Hang from a pair of gym rings and the upward support forces of the rings will always

add up to equal your weight

If an object falls with constant acceleration, the velocity of the object must

continually change by the same amount each second

An object in mechanical equilibrium is an object a. at rest. b. moving with constant velocity. c. having no acceleration. d. all of these

d. all of these.

A skydiver steps from a helicopter and falls for 5 s before reaching her terminal velocity. During this 5-s interval, her acceleration

decreases

When an object falls through the air, its velocity increases and its acceleration

decreases

The two measurements necessary for calculating average speed are

distance and time.

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

double

An elephant and a feather fall from a tree through the air to the ground below. The amount of air-resistance force is greater on the

elephant.

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

follow a straight-line path.

According to Newton's law of inertia, the result of walking much of the day is similar to tightening the head of a hammer when its handle hits a solid surface (Figure 2.2 in the text) so that we are actually a little bit shorter in the

evening

A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor

exactly below the midpoint of the ceiling

If a nonrotating object has no acceleration, then we can say for certain that it is

in mechanical equilibrium.

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

inertia, mass, volume...(all the above)

If you are carrying a heavy bag of groceries and bang your hand against the wall, the concept that most explains why you are hurt is

inertia.

One object that has twice as much mass as another object also has twice as much

inertia.

A falling object that has reached its terminal speed continues to gain

neither speed or acceleration