physics 1 & 2 (B)

B

1. Galileo said that if you rolled a ball along a level surface it would A) slow down due to its natural tendency to come to rest. B) keep rolling without slowing down if no friction acted upon it. C) roll as long as its inertia nudged it along. D) roll in the opposite direction.

C

1. The two measurements necessary for calculating average speed are A) acceleration and time. B) velocity and time. C) distance and time. D) distance and acceleration. E) velocity and distance.

B

11. If you toss a ball straight upward at 40 m/s with no air resistance, one second after it reaches the top of its path its speed is A) zero. B) 10 m/s. C) 20 m/s. D) 30 m/s E) 40 m/s.

C

A 1-kg mass at Earth's surface weighs about A) 1 N. B) 5 N. C) 10 N. D) 12 N.

A

A 10-kg block is pushed across a horizontal surface with a horizontal force of 20 N against a friction force of 10 N. The acceleration of the block is A) 1 m/s2. B) 2 m/s2. C) 5 m/s2. D) 10 m/s2.

C

A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is A) the same as the force on the 1-kg book. B) 5 times as much as the force on the 1-kg book. C) 10 times as much as the force on the 1-kg book. D) zero.

A

A 50-N object falling in air experiences 50 N of air resistance. The amount of net force on the falling object is A) 0 N. B) 25 N. C) 50 N. D) 100 N.

C

A block is dragged at constant velocity across a level surface by a force of 6 N. What is the force of friction between the block and the surface? A) less than 6 N B) more than 6 N C) 6 N

A

A boat loaded with a barrel of water floats in a swimming pool. When the barrel of water is poured overboard, the pool level A) rises. B) falls. C) remains unchanged.

B

A bucket of cement is raised by a rope at constant speed at a construction site. The upward force on the bucket supplied by the rope is A) greater than the force of gravity. B) equal to the force of gravity. C) less than the force of gravity.

A

A bullet fired from a rifle begins to fall A) as soon as it leaves the barrel. B) after air friction reduces its speed. C) neither

C

A car traveling at 100 km/h strikes an unfortunate bug that splatters on the windshield. The force of impact is greater on the A) bug. B) car. C) same for both

A

A change in pressure at any point in a confined fluid at rest is transmitted A) undiminished to all points in the fluid. B) to points of lower pressure. C) in the direction of lower energies.

D

A common 5-L metal can will float in air if it is A) evacuated of air. B) filled with a very large amount of helium. C) thrown high enough into the air. D) Nonsense! Unless the can and displaced air weigh the same, the can can't float in air.

B

A completely submerged object always displaces its own A) volume of fluid. B) weight of fluid. C) density of fluid. D) all of the above E) none of the above

B

A given net force propels an object along a straight-line path. If the net force were doubled, its acceleration would A) quadruple. B) double. C) stay the same. D) be half.

A

A hockey puck slides across a frozen pond. If ice friction and air resistance are neglected, the force needed to keep the puck sliding at constant velocity is A) 0 N. B) equal to the weight of the puck. C) the weight of the puck divided by the mass of the puck. D) the mass of the puck multiplied by 10 m/s2. E) none of the above

C

A hunter fires a bullet from a horizontally-held rifle while simultaneously dropping another bullet from the side of the rifle. Which bullet hits the ground first? A) the dropped one B) the fired one C) both hit at the same time

C

A hydraulic device has two pistons, one with a small cross-section area and another piston with a larger cross-section area. If a given force is applied to the small piston, the output force on the larger-area piston will be A) less. B) the same. C) more.

B

A karate chop breaks a board with a blow of 3000 N. The force that acts on the hand during this event is A) less than 3000 N. B) 3000 N. C) more than 3000 N. D) not enough information

A

A parachutist falling at constant velocity is in a state of A) dynamic equilibrium. B) non-dynamic equilibrium. C) being in and out of dynamic equilibrium. D) none of the above

B

A player catches a ball. Consider the action force of the ball against the player's glove. The reaction is the A) player's grip on the glove. B) force of the glove on the ball. C) friction of the ground against the player's shoes. D) muscular effort in the player's arms.

B

A projectile is launched straight upward at 50 m/s. If air resistance is negligible, its speed upon returning to its starting point is A) less than 50 m/s. B) 50 m/s. C) more than 50 m/s.

A

A projectile is thrown into the air at an angle of 50° and lands on a target that is at the same level the projectile started. With no air resistance it will also land on the target if it is thrown at an angle of A) 40°. B) 45°. C) 55°. D) 60°.

B

A push on a 1-k brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kg brick requires the force to be A) just as much. B) 10 times as much. C) 100 times as much. D) one-tenth the amount.

A

A rising balloon is buoyed up with a force equal to the A) weight of air it displaces. B) density of surrounding air. C) atmospheric pressure. D) weight of the balloon and its contents.

B

A rock is thrown upward at 50° with respect to the horizontal. As it rises, its horizontal component of velocity A) increases. B) remains unchanged. C) decreases.

C

A rock is thrown upward at 50° with respect to the horizontal. As it rises, its vertical component of velocity A) increases. B) remains unchanged. C) decreases.

D

A rock suspended by a weighing scale weighs 3 N when submerged in water and 5 N out of water. What is the buoyant force on the rock? A) 8 N B) 5 N C) 3 N D) 2 N

D

A sheet of paper can be pulled from beneath a box of cereal without toppling it if the paper is jerked quickly. This best demonstrates that A) the box has no acceleration. B) there is an action-reaction pair of forces. C) gravity tends to hold the box secure. D) the box has inertia.

C

A space probe in remote outer space continues moving A) because a force acts on it. B) in a curved path. C) even though no force acts on it. D) due to gravity.

C

According to Galileo, inertia is a A) force like any other force. B) special kind of force. C) property of all matter. D) concept opposite to force.

B

According to Newton, the greater the masses of interacting objects, the A) less the gravitational force between them. B) greater the gravitational force between them. C) greater the force between them by the square of the masses.

A

Airplane lift is achieved when air pressure on the bottom of a wing is A) greater than pressure on top. B) less than pressure on top. C) the same as pressure on top.

A

An Earth satellite is in an elliptical orbit. The satellite travels fastest when it is A) nearest the Earth. B) farthest from the Earth. C) neither

B

An Earth satellite is in an elliptical orbit. The satellite travels slowest when it is A) nearest the Earth. B) farthest from the Earth. C) neither

A

An important underlying feature of hydraulic devices is the conservation of A) pressure. B) momentum. C) energy. D) all of the above

D

An object is pulled with three forces: one at 20 N to the right, another at 40 N to the right, and the third at 30 N to the left. The net force is A) 60 N to the right. B) 60 N to the left. C) 30 N to the left. D) none of the above

A

An object that has twice as much mass as another object also has twice as much A) inertia. B) velocity. C) gravitational acceleration.

B

An object weighs 30 N on Earth. A second object weighs 30 N on the Moon. The object with the greater mass is the one on A) Earth. B) the Moon. C) same for each. D) not enough information

A

As an object freely falls, its A) velocity increases. B) acceleration increases. C) both D) none of the above

B

As water in a confined pipe speeds up, the pressure it exerts against the inner walls of the pipe A) increases. B) decreases. C) remains constant if flow rate is constant.

B

Atmospheric pressure is caused by the A) density of the atmosphere. B) weight of the atmosphere. C) temperature of the atmosphere. D) effect of the Sun's energy on the atmosphere.

A

Burl and Paul have a total weight of 1300 N. The tensions in the ropes that support the scaffold they stand on add to 1700 N. The weight of the scaffold itself must be A) 400 N. B) 500 N. C) 600 N. D) 800 N.

D

Compared with a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much A) inertia. B) mass. C) volume. D) all of the above E) none of the above

A

Compared with the period of satellites in orbit close to Earth, the period of satellites in orbit far from Earth is A) longer. B) shorter. C) the same.

C

Earth moves about 30 km/s relative to the Sun. When you jump upward in front of a wall, the wall doesn't slam into you at 30 km/s because the wall A) has too little gravity to influence you. B) moves in the opposite direction to you. C) and you move at the same horizontal speed, before, during, and after your jump. D) has negligible inertia compared with the Sun.

C

Earth pulls on the Moon. Similarly the Moon pulls on Earth, evidence that A) Earth and Moon pull on each other. B) Earth's and Moon's pulls comprise an action-reaction pair. C) both D) none of the above

A

Earth satellites are typically more than 100-km high so as to mainly be above the Earth's A) atmosphere. B) gravitational influence. C) both

C

Escape speed for a rocket is greatest from A) Earth. B) the Moon. C) the Sun.

C

Escape speed from Earth is A) 8 km/s. B) 9.8 km/s. C) 11.2 km/s. D) 42.2 km/s.

C

Fido weighs 120 N and carries Trixie who weighs 40 N on her back. The support force on Fido's feet is A) 40 N. B) 120 N. C) 160 N.

C

For the astronauts inside an orbiting space vehicle, there is no force of Earth's gravity acting on them. This statement is A) always true while in orbit. B) sometimes true while in orbit. C) always false.

D

How far must one travel to completely be beyond Earth's gravity? A) to a region above the Earth's atmosphere B) to a region well beyond the Moon C) to a region beyond the solar system D) forget it; you can't travel far enough

C

If an object's mass decreases while a constant force acts on it, the acceleration A) decreases. B) remains the same. C) increases. D) will be zero.

C

If the Sun were twice as massive, A) its pull on the Earth would double. B) Earth's pull on the Sun would double. C) both D) neither

A

If the mass of Earth somehow increased with no change in radius, your weight would A) increase also. B) decrease. C) remain the same.

B

If you drop an object, it will accelerate downward at a rate of 10 m/s2. If you instead throw it downward, its acceleration (in the absence of air resistance) will be A) less than 10 m/s2. B) 10 m/s2. C) greater than 10 m/s2.

C

If you toss a ball straight upward at 40 m/s, with no air resistance it returns to you at a speed of A) zero. B) 10 m/s. C) 40 m/s. D) more than 40 m/s.

B

Inside a freely falling elevator your A) acceleration is zero. B) weight is zero. C) gravitational interaction with Earth is zero.

A

One-half second after starting from rest, a freely falling object will have a speed of about A) 5 m/s. B) 10 m/s. C) 15 m/s. D) none of the above

C

Passengers in a high-flying jumbo jet feel their normal weight in flight. Passengers in an orbiting space vehicle do not because passengers are A) beyond the main pull of Earth's gravity. B) above the Earth's atmosphere. C) without support forces.

A

Planets would crash into the Sun if it weren't for A) their tangential velocities. B) their vast distances from the Sun. C) the inverse-square law. D) their relatively small masses. E) the fact that they are beyond the main gravitation of the Sun.

A

Suppose you stand on a weighing scale and all of a sudden the atmosphere vanishes. The reading on the scale would A) increase. (because now there is no buoyancy force) B) decrease. C) remain the same.

C

The amount of friction that occurs when two blocks slide against each other depends on A) how much they are pressed together. B) the "stickiness" of atoms on their surfaces. C) both

C

The average speed of a deer traveling a distance of 2 km in a time of one-half hour is A) 1 km/h. B) 2 km/h. C) 4 km/h. D) more than 4 km/h.

D

The force exerted on the tires of a car to directly accelerate it along a road is exerted by the A) engine. B) tires. C) air. D) road.

A

The force required to maintain an object at a constant velocity in free space is equal to A) zero. B) the mass of the object. C) the weight of the object. D) the force required to stop it.

C

The period of a satellite, the time it takes for a complete revolution, depends on the satellite's A) mass. B) weight. C) radial distance.

C

The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much. This is because A) your mass is 100 times less on Jupiter. B) Jupiter is significantly farther from the Sun. C) Jupiter's radius is 10 times Earth's radius. D) you are 100 times more weightless there.

C

The pressure in a liquid depends on liquid A) density. B) depth. C) both D) neither

D

The resistive force of friction occurs for A) solids. B) liquids. C) gases. D) all of the above

B

To steadily (constantly) increase the velocity of something requires a A) steadily increasing force. B) constant force. C) decreasing force. D) none of the above

A

Two objects move toward each other due to gravity. As the objects get closer and closer, the acceleration of each A) increases. B) decreases. C) remains constant.

A

Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them A) increases. B) decreases. C) remains constant.

B

Two people, one twice as massive as the other, attempt a tug-of-war with 12 m of rope on frictionless ice. After a brief time, they meet. The heavier person slides a distance of A) 3 m. B) 4 m. C) 5 m. D) 6 m.

B

What is the buoyant force acting on a 10-ton ship floating in the ocean? A) less than 10 tons B) 10 tons C) more than 10 tons

B

When Galileo rolled a ball down an incline and up another incline, he found that the ball rolled nearly to A) its initial height. B) halfway its original height. C) three quarters its original height. D) higher than its original height.

C

When a ball increases in speed by the same amount each second, its acceleration A) also increases each second. B) decreases each second. C) is constant. D) varies.

B

When a suction cup sticks to a wall it is A) pulled to the wall by the vacuum. B) pushed to the wall by the atmosphere. C) both D) neither

B

When an object is partly or wholly immersed in a liquid, it is buoyed up A) by a force equal to its own weight. B) by a force equal to the weight of liquid displaced. C) and floats because of Archimedes' principle. D) but sinks. E) none of the above

A

When gas in a container expands to twice its volume at constant temperature, the gas pressure A) is half. B) doubles. C) quadruples. D) remains the same.

B

When gas in a container is squeezed to half its volume, its density A) halves. B) doubles. C) quadruples. D) remains the same.

B

When sign painters Burl and Paul stand on opposite ends of a scaffold, the tensions in each of the two supporting ropes A) are equal. B) depend on the relative weights of Burl and Paul. C) combine to equal zero. D) none of the above

C

When you stand at rest on a pair of bathroom scales, the readings on the scales will always A) each be half your weight. B) each equal your weight. C) add to equal your weight. D) add up to more than your weight.

C

When you stand on tiptoes on a bathroom scale, is there an increase in the weight reading, the pressure on the scale, or both? There is an increase in the pressure on the scale but not the weight. 2. Water pressure at the bottom of a lake depends on the A) weight of water in the lake. B) surface area of the lake. C) depth of the lake. D) all of the above

B

Whenever the net force on an object is zero, its acceleration A) may be zero. B) is zero. C) and velocity are the same. D) none of the above

D

Which has zero acceleration? A) an object at rest B) an object moving at constant velocity C) an object in mechanical equilibrium D) all of the above

C

You toss a ball upward where air resistance is negligible. After the ball leaves your hand the force on it A) gradually decreases until the ball reaches the top of its path. B) first acts upward and then downward after it reaches the top. C) is the single force due to gravity, always directed downward.

B

You're driving in a car at 50 km/h and bump into a car ahead traveling at 48 km/h in the same direction. The speed of impact is A) zero. B) 2 km/h. C) 48 km/h. D) 50 km/h. E) 98 km/h.

A

You're lying on the sand on a breezy day when a pesky fly wishes to join you. The breeze is blowing at a steady 2 m/s. In order for the fly to land on you it should hover over you while flying A) against the breeze at 2 m/s. B) with the breeze at 2 m/s. C) faster than 2 m/s. D) about 4 m/s relative to the breeze.