PHSC 235 FINAL REVIEW

A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before striking the water

-is the same for each bullet

Whenever the net force on an object is zero, its acceleration

-is zero

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 force is a vector quantity because it has both

-magnitude and direction

A kilogram is a measure of an object's

-mass

A heavy rock and a light rock in free fall have the same acceleration. The reason the heavy rock doesn't have a greater acceleration is that the

-ratio of force to mass is the same

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

-same for both

The resistive force of friction occurs for

-solids -liquids -gases -ALL OF THESE

Your weight is

-the gravitation attraction between you and the Earth

A sheet of paper can be withdrawn from under a container of mil without toppling it if the paper is jerked quickly, This best demonstrates that

-the milk carton has inertia

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

-the one on the Moon

compared with the mass of a certain object on Earth, the mass of the same object on the Moon is

-the same

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

Two objects of the same size, but unequal weights are dropped from a tall tower. taking air resistance into consideration, the object to hit the ground first will be the

-they both hit at the same time

As an object freely falls, its

-velocity increases

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

-water resistance that will soon act upward on the diver -air resistance the diver encounters while falling -the attraction to the planets, stars, and every particle in the universe -all of these -NONE OF THESE

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

-zero

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

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

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

-5N

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

-5m/s

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

-6km/h/s

Which has the greater mass?

-AUTOMOBILE BATTERY -king-size pillow -both about the same

the scientist to first introduce the concept of inertia was

-Galileo

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

-Suzie, surprisingly -Arnold of course -BOTH THE SAME, INTERESTINGLY ENOUGH

A Mack truck and a Volkswagon traveling at the same speed have a head on collision. The vehicle to undergo the greatest change in velocity will be the

-Volkswagon

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

-about 30m/s

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

-add equal to your body weight

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

-add up to equal your weight

Your friend says that the heavyweight champion of the world cannot exert a force of 50-N on a piece of tissue paper with his best punch. The tissue paper is held in midair, no wall, no tricks. You...

-agree that it can't be done

An object in mechanical equilibrium is an object

-all of the above

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

which has zero acceleration? An object

-at rest -in mechanical equilibrium -moving at constant velocity -ALL OF THE ABOVE

A heavy object and a light object are dropped at the same time from rest in the vacuum. the heavier object reaches the ground

-at the same time as the lighter object

suppose you're coasting in a car at 60km/h and apply the brakes until you slow to 40km/h. When you suddenly release the brake, the care tends to

-continue moving at 40km/h in the absence of forces

Suppose a particle is being accelerated through space by a 10-N force. Suddenly the particle encounters a second force of 10 N in the opposite direction of the first force. The particle with both forces acting on it

-continues at the speed it had when it encountered the second force

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 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

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 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

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

-experiment

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 ball

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

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

an object is propelled along a straight-line path in space by force. If the mass of the object somehow becomes twice as much, its acceleration

-halves

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

-how much they are pressed together -the stickiness of atoms on their surfaces -BOTH OF THESE

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

-in mechanical equilibrium

If an object's mass is decreasing while a constant force is applied to the object, the acceleration

-increases

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

An apple weighs 1 N.The Magnitude of net force on the apple when it is in free-fall is

-1 N

A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is about

-10

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

-10 N

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

-10-N

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

-100m/s

A 1-kg rock that weighs 10N thrown straight upward at 20m/s. Neglecting air resistance, the net force that acts on it when it is half way to the top of its path is

-10N

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

-10m/s

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

-10m/s

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

-10m/s/s

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

-10m/s/s

a car has a mass of 1000kg and accelerates at 2m/s. What is the magnitude of the force exerted on the car?

-2000 N

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

-20km/h

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

-20m/s

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

-220

A girl pulls on a 10-kg wagon with a constant force of 30N. What is the wagon's acceleration in meters per second per second?

-3.0

A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 6 s. The speed of the car just before the brakes were applied was

-30m/s

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

-4000N

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

-500 N

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

-500 N

A person is attracted toward the center of the Earth by a 500-N gravitation force. The force of attraction of the Earth toward the person is

-500-N

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 10s?

-50m/s