Physical Science

2000 N

A 1000-kg truck moving at 10 m/s that brakes to a stop in 5 s has an average braking force of 2000 N.4000 N.5000 N.3000 N.1000 N.

the same

A 50-kg sack is lifted 2 m in the same time as a 25-kg sack is lifted 4 m. The power expended in raising the 50-kg sack compared to the power used to lift the 25-kg sack is

both at the same time

A ball rolls off the edge of a table at the same time another ball drops vertically from the same table. The ball to hit the floor first is the rolling ball. dropped ball. both hit at the same time

60 degrees

A ball tossed at an angle of 30°with the horizontal will go as far downrange as one tossed at the same speed at an angle of 45° 60° 75° None of the above.

one quarter from the bottom

A block of ice sliding down an incline has one-quarter its maximum potential energy one-quarter from the top .one-quarter from the bottom .half the way down .need more information

40J

A bow is drawn so that it has 40 J of potential energy. When the arrow is fired its kinetic energy is ideally 40 J.less than 40 J.more than 40 J.

as it leaves the barrel

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

impulse

A cannonball fired from a long-barrel cannon will have a greater muzzle velocity because the cannonball receives a greater

30% of the energy input to useful work—70% of the energy input will be wasted.

A certain machine is 30% efficient. This means the machine will convert 30% of the energy input to useful work—70% of the energy input will be wasted. 70% of the energy input to useful work—30% of the energy input will be wasted. As strange as it may seem, both of the above. None of the above.

common lever

A common pulley acts similar to a

100 m

A gun with a muzzle velocity of 100 m/s is fired horizontally from a tower. Neglecting air resistance, how far downrange will the bullet be 1 s later? 50 m 100 m 98 m 500 m none of the above

both hit at the same time

A hunter fires a bullet from a horizontally—held rifle while simultaneously dropping another bullet from the side of the rifle. The bullet to hit the ground first is the dropped one.the fired one.both hit at the same time

always false

A hydraulic press, like an inclined plane, is capable of increasing energy. true or false

50%

A jack system will increase the potential energy of a heavy load by no more than 1000 J with a work input of 2000 J. The efficiency of the jack system is at most

bounces upon impact

A karate chop is more effective if one's hand follows through upon impact .extends the time upon impact. bounces upon impact.

100 joules

A melon is tossed straight upward with 100 J of kinetic energy. If air resistance is negligible the melon will return to its initial level with a kinetic energy of

40 J because w=force x distance

A music console is pushed 2 m by a force of 20 N. The work done on the console is 2 J.10 J.20 J.40 J.80 J.

1 unit

A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both move with a combined momentum of less than 1 unit. more than 1 unit. 1 unit. not enough information

5m

A stone is thrown horizontally from the top of a cliff. One second after leaving your hand it drops a vertical distance of 5 m.15 m.10 m.

closest to Earth

Acceleration is greatest for a satellite in elliptical orbit when it is closest to Earth.farthest from Earth.same at both places

more the gravitational force between them

According to Newton, the closer gravitationally interacting objects are to each other, the constancy of the force between them. more the gravitational force between them. less the gravitational force between them.

the same as its potential energy

After rolling half-way down an incline, a marble's kinetic energy is

a lower speed

An astronaut floating alone in outer space throws a baseball. If the ball moves away at 20 m/s, the astronaut will move in the opposite direction at

a lower speed

An astronaut floating alone in outer space throws a baseball. If the ball moves away at 20 m/s, the astronaut will move in the opposite direction at a lower speed. a higher speed. 20 m/s.more information needed none of the above

momentum

An iron ball and wooden ball of the same size are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater

location

An object may have potential energy because of its momentum.location.acceleration.speed.none of the above

increases

As a bowling ball that rolls off the edge of a table falls, its vertical component of motion remains constant.increases.decreases.

5 meters below the dashed line

As the ball leaves the girl's hand, one second later it will have fallen 10 meters. 5 meters below the dashed line. less than 5 meters below the straight-line path. None of the above.

weak force

Compared to other fundamental forces, the Universal Gravitational Constant G indicates gravity to be a relatively strong force.weak force.extremely strong force.

longer time to stop

Compared with falling on a wooden floor, a wine glass may not break when it falls on a carpeted floor because of

greater

Compared with the period of satellites in orbit close to Earth, the period of satellites in orbit far from Earth is greater.less.the same.not enough information

Fd = Δ1/2mv2.

Consider a problem that asks for the distance a fast-moving crate slides across a factory floor in coming to a stop. The most useful equation for solving this problem is F = ma. Ft = Δmv. KE = 1/2mv2. Fd = Δ1/2mv2.

twice as much

Consider two planets in space that gravitationally attract each other. If the mass of one planet is doubled, and the distance between them doesn't change, then the force between them is one-quarter. half as much. four times as much. twice as much. none of the above

A fast-moving car hitting a haystack or hitting a cement wall produces vastly different results. Both experience a. the same change in momentum b. the same impulse c. the same force d. both a and b

D

Uranus and Neptune

Dwarf planet Pluto was discovered by perturbations of Uranus and Neptune.Saturn.Jupiter.all of the above

the Sun

Escape speed for a rocket is greatest from the Moon.the Sun.Earth.same for each

11.2 km/s

Escape speed from Earth is 11.2 km/s.8 km/s.42.2 km/s.9.8 km/s.

1s

If a projectile is fired straight up at a speed of 10 m/s, neglecting air resistance, the time it takes to reach the top of its path is 1 s.10 s.2 s.not enough information

double

If the mass of one planet is somehow doubled, the force of gravity between it and a neighboring planet would double. quadruple reduce by half. reduce by one quarter.

quadruples

If the masses of two planets are each somehow doubled, the force of gravity between them doubles. quadruples. reduces by half. reduces by one quarter.

twice

If you do work on an object in half the time, your power output is the same.half.twice.

twice as much work

If you push an object twice as far while applying the same force, you do

accelerates upward

If you weigh yourself in an elevator, you'll weigh more when the elevator moves upward. moves downward. accelerates upward. All of the above.

25 cm

In an ideal pulley system, a woman lifts a 100-N crate by pulling a rope downward with a force of 25 N. For every one-meter length of rope she pulls downward, the crate rises 50 centimeters. 45 centimeters. 25 centimeters. None of the above.

500 N

In raising a 5000-N piano with a pulley system, for every 1 m of rope pulled down, the piano rises 0.1 m. Ideally, this means the force needed to lift the piano is 500 N.5000 N.50 N.not enough information

atmospheric pressure

In the vacuum of outer space far from our Sun, there is no atmospheric pressure. gravity. both of these none of the above

less than 8 km/s

Minimal orbit speed about Earth is about 8 km/s. Minimal orbital speed for a satellite about the Moon would be greater than 8 km/s.less than 8 km/s.about 8 km/s.

When a dish falls, will the change in momentum be less if it lands on a carpet than if it lands on a hard floor?

No, both are the same

the absence of a support force

Occupants of the International Space Station experience weightlessness due to the absence of a support force .no inertia in space .rotation of the station. the absence of Earth gravity at that altitude.

500 N

Phil stands at rest with both feet on a scale that reads 500 N. After he gently lifts one foot, the scale reads more than 500 N.less than 500 N.500 N.

10 joules go to warming the bow

Suppose the potential energy of a drawn bow is 50 joules, and the kinetic energy of the shot arrow is 40 joules. Then energy is not conserved. 10 joules go to warming the bow. 10 joules go to warming the target. 10 joules is mysteriously missing.

its orbital period is 24 hours.

The Earlybird communication satellite hovers over the same point on Earth's equator indefinitely because it is beyond the main pull of Earth gravity. its orbital period is 24 hours. forces other than Earth's gravity act on it. it is kept aloft by ground control. it pulls as hard on Earth as Earth pulls on it.

its tangential velocity causes it to fall around as well as toward Earth.

The Moon continually falls toward Earth, but doesn't get closer because its tangential velocity causes it to fall around as well as toward Earth. the distance of fall is very small. gravitation is extremely weak at the Earth-Moon distance.

bottom of its swing

The bob of a simple pendulum has its maximum kinetic energy at the midpoint between top and bottom of its swing .at all points along its path of swing. bottom of its swing. top of its swing.

time the force acts

The distinction between impulse and force involves the difference between acceleration and velocity. distance the force acts. time the force acts. mass and its effect on resisting a change in momentum.

masses and distance apart

The force of gravity between two planets depends on their masses and distance apart. planetary atmospheres. rotational motions. All of the above.

all the above

The massive ram of a pile driver falling from rest strikes a pile with a speed that depends on the initial potential energy of the ram .initial height of the ram. distance the ram falls. all of the above

varies

The speed of a satellite in an elliptical orbit varies. remains constant. acts at right angles to its motion. All of the above.

parallel to the surface of Earth

The tangential velocity of an Earth satellite is its velocity perpendicular to the surface of Earth. parallel to the surface of Earth .attributed to satellites moving in any direction.

Sun

The ultimate source of energy from fossil fuels is the

remains the same

The velocity of a typical projectile can be represented by horizontal and vertical components. Assuming negligible air resistance, the horizontal component along the path of the projectile increases. decreases. remains the same. Not enough information.

none of the above

The work done in braking a moving car to a stop is the force of tire friction stopping distance. If the initial speed of the car is doubled, the stopping distance is actually less. about the same. twice. None of the above.

time of catch is increased

To catch a fast-moving softball with your bare hand, you extend your hand forward just before the catch and then let the ball ride backward with your hand. Doing this reduces the catching force because the

0.5 m/s

Two identical freight cars roll without friction towards each other on a level track. One car rolls at 2 m/s and the other car rolls at 1 m/s. After the cars collide, they couple and roll together with a speed of 0.33 m/s.0.67 m/s.0.5 m/s.1.0 m/s.none of the above

increases

Two objects move toward each other due to gravity. As the objects get closer and closer, the acceleration of each decreases. increases. is not affected.

3 m/s

What is the speed of a 4-kg ball with a momentum of 12 kg∙m/s?

5000J

When Danny Diver who weighs 500 N steps off a diving board 10 m above the water, he hits the water with kinetic energy of

decreases

When Freddy Frog drops vertically from a tree onto a horizontally-moving skateboard, the speed of the skateboard decreases. increases. neither decreases nor increases.

the time of contact is increased

When a boxer is moving away from a punch, the force experienced is reduced because the force is less effective .the time of contact is increased. momentum transfer is reduced. all of the above

increased

When a boxer moves into an oncoming punch, the force experienced is increased. decreased .no different, but the timing is different .all of the above

masses

When a cannon fires a cannonball at a given speed, the smaller recoil speed of the cannon is due to differences in masses .momenta. forces. times.

Outruns the influence of Earth's gravity but is never beyond it

When a projectile achieves escape speed from Earth, it forever leaves Earth's gravitational field. outruns the influence of Earth's gravity but is never beyond it. comes to an eventual stop, eventually returning to Earth at some future time. All of the above.

a circle

When a satellite travels at constant speed, the shape of its path is a circle. an ellipse. an oval that is almost elliptical. a circle with a square corner, as seen throughout your book.

less

When an elevator accelerates downward, your weight reading is greater. less. zero. the normal weight.

Greater

When an elevator accelerates upward, your weight reading on a scale is greater. less. zero. the normal weight.

downward, g.

When no air resistance acts on a fast-moving baseball, its acceleration is downward, g. due to a combination of constant horizontal motion and accelerated downward motion. opposite to the force of gravity. centripetal.

zero

When the elevator cable breaks, the elevator falls freely so your weight reading is greater. less. zero. the normal weight.

long

When you can't escape being hit by a fast-moving object, you'll suffer a smaller force if the collision time is

twice the momentum

When you ride your scooter you have momentum. When you ride twice as fast you have almost twice the momentum. twice the momentum. four times the momentum. none of the above

at the same speed

When you simultaneously drop a light tennis ball and a heavy bowling ball, they hit the floor

matches the curved surface of Earth.

When you toss a projectile sideways, it curves as it falls. It will be an Earth satellite if the curve it makes matches the curved surface of Earth. results in a straight line. spirals out indefinitely. None of the above.

the same

Whether a truck comes to a stop by crashing into a haystack or a brick wall, the impulse is

fossil fuel power

Which of these forms of energy is NOT renewable? wind power solar power photovoltaic power fossil fuel power

no horizontal forces act on it

With no air resistance a projectile fired horizontally maintains its horizontal component of velocity because no forces act on it. of no initial vertical component of velocity. no horizontal forces act on it. all of the above none of the above

40 degrees

With no air resistance, a projectile fired at 50° has the same range as if it were fired at 40°.55°.60°.45°.

all of the above

Without air resistance, a projectile fired horizontally at 8 km/s from a mountain top will accelerate downward at g as it moves horizontally. return to its starting position and repeat its falling behavior .trace a curve that matches Earth's curvature. all the above none of the above

Neptune

Wobbles in the path of Uranus led to the discovery of Mars.Jupiter.Neptune.all of the abovenone of the above

on a sloped surface

Work is done by gravity on a bowling ball that rolls on a sloped surface. along a horizontal surface. both of these none of the above

Does a car hoisted for repairs in a service station have increased potential energy relative to the floor?

Yes comment: if the car were twice as heavy, its increase in potential energy would be twice as great

Must a car with momentum have kinetic energy?

Yes, due to motion alone

A moving object has a. momentum b. energy c. speed d. all the above

all the above

The work done in braking a moving car to a stop is the force of tire friction x stopping distance. If the initial speed of the car is doubled, the stopping distance is a. actually less b. about the same c. twice d. none of the above

d. none of the above

What are examples of potential energy?

drawn bow, stretched rubber band, raised ram of pile driver

Freight Car A is moving toward identical Freight Car B that is at rest. When they collide, both freight cars couple together. Compared with the initial speed of Freight Car A, the speed of the coupled freight cars is

half

When the force that produces an impulse acts for twice as much time, the impulse is

increased by two times

If you push against a stationary brick wall for several minutes, you do no work

on the wall

Kinetic energy is a ______ quantity

scalar

Work is done in lifting a barbell. How much work is done in lifting a barbell that is twice as heavy the same distance?

twice as much

You do work when pushing a cart. If you push the cart twice as far with the same constant force, then the work you do is

twice as much

momentum is a _____ quantity

vector