How can we help?

You can also find more resources in our Help Center.

66 terms

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

500 N

If Earth's mass decreased to 1/2 its original mass with no change in radius, then your weight would...

decrease to 1/2 your original weight

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

earth

A woman who normally weights 400 N stands on top of a very tall ladder so she's one earth-radius above the earth's surface. How much would she weigh there?

100 N

Two objects move toward each other because of gravity. As the objects get closer, the force between them...

increases

Consider two planets in space that gravitationally attract each other. If the masses of both planets is doubled, and the distance between them is doubled, then the force between them is...

less

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

practically the same weight

Each of us weighs a tiny bit less inside the ground floor of a skyscraper than we do on the ground away from the skyscraper. The reason for this is...

the mass of the building attracts us upward slightly

According to Newton, the greater the masses of interacting objects...

the greater the gravitational force between them

Inside a freely falling runaway elevator, what is zero?

your apparent weight

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

remains unchanged

Throw an object at an angle upward. With no gravity it will follow a straight-line path. But because of gravity, at the end of 1 s, how far below the straight line is it?

5 m

A bullet fired from a rifle begins to fall...

as soon as it leaves the barrel

True or False: an earth satellite is simply a projectile freely falling around the earth

true

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

0.5 s

A projectile is thrown into the air at an angle of 50 degrees and lands on a target that is at the same level the projectile started. It will also land on the target if it is thrown at an angle of...

40 degrees

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

1 s

A ball is thrown upwards and caught when it comes back down. Neglecting air resistance, the speed with which it is caught is...

same as the speed it had when thrown upwards

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

longer than the ascent time

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

2 s

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

The reason the Moon doesn't crash into the Earth is that...

the Moon has a sufficient tangential speed

Without air resistance, a projectile fired horizontally at 8 km/s from atop a mountain will: A) accelerate downward at g as it moves horizontally, B) return later to its starting position and repeat its falling behavior, or C) trace a curve that matches the earth's curvature

all of these

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

their tangential velocities

The fastest moving planet in a solar system is...

the planet nearest the Sun

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

atmosphere

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

The speeds of the planets about the Sun depend on...

their distances from the Sun

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

11 km/s

Minimal orbit speed about Earth is about 8 km/s. Minimal orbit speed about Jupiter would be...

more than 8 km/s

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

radial distance

The earlybird communication satellite hovers over the same point on earth's equator indefinitely. This is because...

its orbital period is 24 hours

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

longer

From earth, one satellite appears to overtake another. The faster satellite is...

lower

The force of gravity works on a satellite when it is in...

elliptical orbit

Compared to a bare of pure gold, the density of a pure gold ring is...

the same

Compare to the density of a kilogram of feathers, the density of a kilogram of lead is...

more

If the mass of an object were to double while its volume remains the same, its density would...

double

The weight of air in a bathtub (about 1/3 m cubed) is about the same weight of a...

pound of butter

A dam is thicker at the bottom than at the top because...

water pressure is greater with increasing depth

The pressure at the bottom of a jug filled with water does NOT depend on...

surface area of the water

There is a legend of a Dutch boy who bravely held back the Atlantic Ocean by plugging a leak near the top of a dike with his finger until help arrived. What is most likely?

the force on his finger would have been less than 1 N

Pumice is a volcanic rock that floats. Its density is...

less than the density of water

A completely submerged object always displaces its own...

volume of fluid

What is the weight of water displaced by a 100-ton floating ship?

100 tons

The buoyant force on an object is least when the object is...

partly submerged

Lobsters live on the bottom of the ocean. The density of a lobster is...

greater than the density of seawater

Two life preservers have identical volumes, but one is filled with styrofoam while the other is filled with sand. When the two life preservers are fully submerged, the buoyant force is greater on the one filled with...

same on each as long as their volumes are the same

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

2 N

Ice cubes submerged at the bottom of a liquid mixture indicate that the mixture...

is less dense than ice

The volume of water displaced by a floating 20-ton boat is...

the volume of 20 tons of water

A liter-sized block of ordinary wood floats in water. The amount of water displaced is...

less than 1 L

Is the buoyant force greatest on a submerged 1 cubic cm block of lead or 1 cubic cm block of aluminum?

same on each

Atmospheric pressure is caused by the...

weight of the atmosphere

Does the air in a room have mass, energy, or weight?

all of these

A suction cup sticks to a wall. It is...

pushed to the wall by the atmosphere

It would be easier to pull evacuated Magdeburg hemispheres apart when they are...

20 km above the ocean surface

In a vacuum, a marshmallow becomes...

larger

Wind blowing over the top of a hill...

decreases atmospheric pressure there

The Bernoulli effect causes passing ships to be drawn together when the ships are close and moving in...

either the same or opposite direction

Suspend a pair of ping pong balls from two strings so there is a small space between them. If you blow air between the balls, they will swing...

toward each other

equation for density

density=mass/volume

equation for weight density

weight density=weight/volume

equation for pressure

pressure=force/area

equation for liquid pressure

liquid pressure=weight density x depth

Boyle's Law

P1V1=P2V2