Physical Science Chapter 4

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If a projectile is fired straight up at a speed of 10 m/s, neglecting air resistance, the total time to return to its starting position is

2 s

If there were no gravity, a ball thrown upward at an angle would follow a straight-line path. Due to gravity, however, at the end of 2 s it is

20 m below the straight line

A softball player determines her pitching speed by throwing a ball horizontally from an elevation of 20 m above the ground. The ball lands 50 m downrange. What is her pitching speed?

25 m/s

For each 8-km segment of a satellite in close Earth orbit, the "drop" toward Earth is about

5 m

Your weight is equal to mg when you are

Firmly supported on a horizontal service and in equilibrium.

The tangential velocity of an Earth satellite is its velocity

Parellel to the surface of Earth

Perturbations of planets are due to

interplanetary forces

Your weight is defined to be the force

you exert against a supporting surface

Inside a freely-falling elevator your

Weight is zero

You can experience weight

all of the above

Neglecting air resistance, after a ball leaves your hand when you toss it upward, the force on it

is only the force due to gravity, always directed downward

A projectile is launched straight upward at 50 m/s. Neglecting air resistance its speed upon returning to its starting point is

50 m/s

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

500 N

What is the force of gravity on a 500-N woman standing on Earth's surface?

500 N

According to Newton, the greater the masses of interacting objects, the Select one:

Greater than the gravitational force between them.

With no air resistance a projectile fired horizontally maintains its horizontal component of velocity because

No horizontal force acts on it.

If the masses of two planets doubles and the distance between them also doubles, the force between them would be

None of the above

The force of gravity on a bowling ball rolling along a horizontal surface doesn't change its speed because the force is

Perpendicular to its direction of motion

As a bowling ball that rolls off the edge of a table falls, its horizontal component of motion

Remains constant

A woman who normally weighs 400 N stands on top of a very tall ladder so she is one Earth-radius above Earth's surface. What is her weight there?

100 N

A ball is thrown horizontally from the top of a tall cliff. Three seconds later, the ball has fallen a vertical distance of

45 m

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

An object is placed exactly halfway between the Earth and the Moon. The object will fall toward the

Earth

The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much because

Jupiters radius is ten times Earths radius

According to Newton, the greater the distance between gravitationally interacting objects, the

Less than the gravitational force between them.

For the astronauts inside an orbiting space vehicle the force of gravity that acts on them is

Mainly due to Earth below

According to Newton, the closer gravitationally interacting objects are to each other, the

More the gravitational force between them.

The force of gravity on a satellite in circular orbit doesn't change its speed because the force is

Perpendicular to its direction of motion

The force of gravity acts on all apples on an apple tree. Some apples are twice as far from the ground. Such twice-as-high apples of the same mass, have

Practically the same weight

A rock is thrown upward at 50° with respect to the horizontal. As it rises, its horizontal component of velocity

Remains unchanged

Weight can be simulated in a space vehicle if the vehicle is

Rotating

This chapter states a link between Newton's Universal Law of Gravity and

The US constituition

Strictly speaking, when you step off a curb you are momentarily

Weightless

An airplane flying overhead drops a care package directly over Mike at rest in his Corvette. Neglecting air resistance, the package will land

Well ahead of Mike and his corvette

A "weightless" astronaut in an orbiting space vehicle is

Without a support force

Passengers in a high-flying jumbo jet feel their normal weight in flight, whereas passengers in an orbiting space vehicle do not because they are

Without support forces

A dropped ball gains speed because

a gravitational force acts on it

You experience weightlessness

all of the above

If Earth's mass somehow doubles with no change in its size, and your mass remains the same, your weight

also doubles

If your mass doubles, your weight

also doubles

A bullet fired from a rifle begins to fall

as soon as it leaves the barrel

Each of us weighs slightly less inside the ground floor of a skyscraper than we do on the ground away from the skyscraper because the

mass of the building attracts us upward slightly.

The amount of gravitational force that acts on a space vehicle that orbits Earth is

nearly as much as the vehicle's weight on Earth's surface.

An object is thrown vertically into the air. Because of air resistance, the time for its descent will be

Longer than the ascent time

Wobbles in the path of Uranus led to the discovery of

Neptune

Why doesn't the Moon fall toward Earth like apples do?

moon does fall but due to its tangential motion it also falls around Earth

Pioneer 10 was able to escape the solar system by

"bouncing off" Jupiter like a tennis ball bouncing off an approaching tennis racket.

Consider a monkey wrench released at rest at the far edge of the solar system that drops to Earth by virtue of only Earth's gravity. The wrench will strike Earth's surface with a speed of about

11 km/s

Escape speed from Earth is

11.2 km/s

A supplier wants to make a profit by buying gold by weight at one altitude and selling it at the same price per newton at another altitude. The supplier should

Buy at a high altitude and sell at a low altitude.

The Universal Gravitational Constant G was first measured by

Cavendish

Acceleration is greater for a satellite in elliptical orbit when it is

Closest to Earth

If Earth's mass decreased to one-half its original mass with no change in radius, your weight would

Decreases to one-half

A vertically oriented rocket that is able to sustain a continuous upward velocity of 8 km/s will

Eventually escape from Earth

An Earth satellite in an elliptical orbit travels slowest when it is

Farthest from the Earth

Compared to the speed a satellite loses when traveling from nearest to farthest points from Earth, the speed gained when returning from farthest to nearest is

The same

The planet Neptune was discovered by perturbations of

Uranus

Dwarf planet Pluto was discovered by perturbations of

Uranus and Neptune

Compared to other fundamental forces, the Universal Gravitational Constant G indicates gravity to be a relatively

Weak force

The hang time of an athlete who moves horizontally 2.0 m during a 1.25-m-high jump is

About 1 s

As a bowling ball that rolls off the edge of a table falls, its vertical component of motion

Increases

After a stone that is thrown straight up reaches the top of its path and then falls downward, its acceleration is

The same as at the top of its path

An outcome of universal gravitation is that

all of the above

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 radial velocity of an Earth satellite is its velocity

perpendicular to the surface of Earth.

Newton discovered

that gravity is universal

A bullet fired horizontally hits the ground in 0.5 s. If it had been fired with twice the velocity it would have hit the ground in

0.5 s

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

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?

100 M

A softball player determines her pitching speed by throwing a ball horizontally from an elevation of 5 m above the ground. The ball lands 20 m downrange. What is her pitching speed?

20 m/s

Ignoring air resistance, what maximum speed can be given to a horizontally moving tennis ball as it clears the net 1.25 m high to remain within the edge of the court, which is 12.0 m from the bottom of the net?

24 m/s

Earth satellites are typically more than 100-km high so as to mainly be above the Earth's

Atmosphere

An airplane flies at 40 m/s at an altitude of 50 m. The pilot drops a heavy package that falls to the ground below. Neglecting air resistance, the package will land

Beneath the plane

A very massive object A and a less massive object B move toward each other under the influence of gravity. Which force, if either, is greater?

Both forces on each other are the same.

If the radius of the Earth somehow increased with no change in mass, your weight would

Decrease

If Earth's mass somehow decreased with no change in its radius, your weight would

Decrease also

A rock is thrown upward at 50° with respect to the horizontal. As it rises, its vertical component of velocity

Decreases

When the distance between a pair of stars doubles, the force between them

Decreases by one-quarter

Nellie tosses a ball upward at an angle. Assuming no air resistance, which component of velocity changes with time?

The vertical component

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

Twice as much

Planets wobble in their orbits due to

the gravitational attraction to other planets

Inside a freely-falling elevator you would have no

weight

In the vacuum of outer space far from our Sun, there is no

Atmospheric pressure

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

Both hit at the same time

Air resistance on a high-speed projectile shortens its

Both of these

An Earth satellite is simply a projectile

freely falling around the earth

The Sun is spherical due to

gravitation

A projectile is launched at an angle of 15° above the horizontal and lands downrange. With no air resistance, what other projection angle for the same speed would produce the same downrange distance?

75 degrees

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

Both hit at the same time.

One second after a ball rolls off the edge of a horizontal surface at a speed of 10 m/s,

Both of these

The identities of dark energy and dark matter are

Both of these

How far away from Earth must one travel to completely be beyond Earth's gravity?

Forget it, you can't travel far enough.

At some point between Earth and the Moon, the forces due to gravity on a space traveler would be the same when this point is

nearer the Moon

Planets would crash into the Sun if it weren't for

their tangential velocities

An Earth satellite in an elliptical orbit travels fastest when it is

Nearest the Earth

A satellite in an elliptical orbit travels at constant

None of the above

Escape speed for a rocket is greatest from

the Sun

The fastest moving planet in a solar system is the

the planet nearest the sun

The speeds of the planets about the Sun depend on

their distances from the sun

With no air resistance, a projectile fired at 60° has the same range as if it were fired at

30 degrees

With no air resistance, a projectile fired at 50° has the same range as if it were fired at

40 degrees

If there were no gravity, a ball thrown upward at an angle would follow a straight-line path. Due to gravity, however, at the end of 1 s it is

5 m below the straight line

The parabolic path of a cannonball fired from a mountain top is actually

A segment of an ellipse

A satellite near Earth makes a full circle in about 90 minutes. Much farther from Earth, say at the distance to the Moon, time for a full circle would be

About 28 days

Without air resistance, a projectile fired horizontally at 8 km/s from a mountain top will

All of the above

The circular path of a satellite orbiting Earth is characterized by a constant

All the above

Traveling from Earth to the Moon requires that a rocket have

Any sustained speed if time isn't a factor

The International Space Station orbits at an average 360-km altitude so that it is mainly above Earth's

Atmosphere

To drop a package to Earth from a satellite, project it

Behind at satellite speed

The planet Jupiter takes a longer time to travel around the Sun than Earth because Jupiter

Both of these

Two motorcycle stunt drivers, one light and the other much heavier, ride their motorcycles up and off an inclined ramp at identical speeds. They both rise in the air and land downrange. Neglecting air resistance, the one to attain the greatest height and greatest range is the

Both the same

Consider two planets in space that gravitationally attract each other. If the masses of both planets are doubled, and the distance between them doesn't change, then the force between them is

Four times as much

Minimal orbit speed about Earth is about 8 km/s. Minimal orbital speed for a satellite about Jupiter would be

Greater than 8 km/s

If the radius of the Earth somehow decreased with no change in mass, your weight would

Increases

Two objects move toward each other due to gravity. As the objects get closer and closer, the acceleration of each

Increases

Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them

Increases

When the distance between a pair of stars decreases by half, the force between them

Increases four times as much.

The Earlybird communication satellite hovers over the same point on Earth's equator indefinitely because

Its orbital period is 24 hours

A lunar month is about 28 days. If the Moon were closer to Earth than it is now, the lunar month would be

Less than 28 days

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

Less than 8 km/s

From Earth, one satellite appears to overtake another. The faster satellite that is seen to overtake the other is

Lower

A lunar month is about 28 days. If the Moon were farther from Earth than it is now, the lunar month would be

More than 28 days

Communications and weather satellites always appear at the same place in the sky because these satellites are

Orbiting Earth with a 24 hour period

The period of a satellite, the time it takes for a complete revolution, depends on the satellite's

Radial distance

A projectile that is fired vertically at 5 km/s from the Earth's surface will

Rise and fall back to Earths surface

A projectile that is fired vertically at 8 km/s from Earth's surface will

Rise and fall back to Earths surface

Escape speed for a rocket is less from

The Moon

Occupants of the International Space Station experience weightlessness due to

The absence of a support force.

A hunter aims a rifle at an angle of 10° above the horizontal. The hunter fires a bullet while simultaneously dropping another bullet from the side of the rifle. The bullet to hit the ground first is

The dropped one

A hunter aims a rifle at an angle of 10° below the horizontal. The hunter fires a bullet while simultaneously dropping another bullet from the side of the rifle. The bullet to hit the ground first is

The fired one

If the Sun were twice as massive,

both of these

Compared with the period of satellites in orbit close to Earth, the period of satellites in orbit far from Earth is

greater

The Moon does not crash into Earth because

moon has a sufficient tangential speed

What holds Earth satellites up so they don't crash into Earth?

nothing, they continually fall fast enough around Earth not to crash

Gravitational force is greater for a satellite in elliptical orbit when it is at the

perigee (closest point)


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