Harrison Physics 13-14

Which of these three produces the greatest tidal effect on you right now? a) Earth b) the moon c) the sun

a) Earth

A satellite near earth makes a full circle in about an hour and a half. how long would it take a satellite located as far away as the moon to orbit earth? a) about 28 days b) a satellite could not be put into such an orbit c) it depends on the mass of the satellite d) about an hour and a half e) none of the above

a) about 28 days

Where does a satellite in an elliptical orbit have the greatest kinetic energy? a) at the point closest to the planet b) exactly at the point halfway to the planet c) at the point farthest from the planet d) anywhere- its kinetic energy is constant e) more information needed

a) at the point closest to the planet

The speed of a satellite in a circular orbit is... a) constant b) not constant c) constantly increasing

a) constant

Gravitation weakens as the inverse square of distance, while tidal forces weaken with the inverse... a) cube of distance b) of distance c) square of distance

a) cube of distance

If the mass of the Earth is increased, with no change in radius, your weight would... a) increase also b) stay the same c) decrease

a) increase also

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

a) its orbital period is 24 hours

The force is gravity on you is greatest when you are standing... a) just below earth's surface b) on Earth's surface c) just above Earth's surface

a) just below earth's surface

Minimal orbital speed about Earth is approximately 8km/s. Minimal orbit speed about the moon would be... a) less than 8km/s b) about 8km/s c) more than 8 km/s

a) less than 8 km/s

If you were to weigh yourself in an elevator that is in free fall, compared to you ordinary weight, you would weigh... a) more b) less, but more than zero c) the same d) zero

a) more

There are two main processes going on in the sun that keep the sun in existence. These processes are gravitation and... a) nuclear fusion b) electrostatic repulsion c) heat absorption

a) nuclear fusion

Consider the gravitational force between Earth and a meteor in outer space. If the meteor moves so its distance from the Earth's center doubles, the gravitational force in the meteor will be... a) one quarter b) half c) double d) quadruple e) eight times greater

a) one quarter

Newton reasoned that the gravitational attraction between Earth and the moon must be... a) reduced by distance b) independent of distance c) directly proportional to distance d) the same at all distances e) all of the above

a) reduced by distance

A projectile is fired vertically from the surface if earth at 10 km/s. The projectile will... a) rise and then fall back to Earth's surface b) go into an elliptical orbit about Earth c) go into a circular orbit about earth d) none of the above

a) rise and then fall back to Earth's surface

If you drop a stone into a whole drilled all the way to the other side of Earth, the stone will... a) speed up until it gets to the center of Earth b) slow down until it reaches the center of Earth c) speed up until it reaches the other side of Earth d) stop at the center of Earth

a) speed up until it gets to the center of Earth

The force of gravity acting on you will increase if you... a) stand on a planet with a radius that is shrinking b) burrow deep inside the planet c) both A and B d) none of the above

a) stand on a planet with a radius that is shrinking

A solar eclipse happens when... a) the moon is between Earth and the sun b) Earth is between the moon and the sun c) the sun is between the earth and the moon

a) the moon is between Earth and the sun

A planet has half the mass of the earth and half the radius. Compared to its weight on Earth, an apple on this planet would weigh... a) twice as much b) one-fourth as much c) half as much d) the same e) zero

a) twice as much

since the earth is attracted to the sun, why doesn't it fall into the sun? a) Because it has too much mass to move toward the sun b) Because it has sufficient tangential velocity c) Because there is an equal force holding it away from the sun d) Because it has too much inertia to move toward the sun e) all of the above

b) Because it has sufficient tangential velocity

Why did Newton think there was a force acting on the moon? a) Because the moon always keeps one side toward Earth b) Because the moon moves in a curved path c) Because there is no air on the moon d) Because the moon is moving e) all of the above

b) Because the moon moves in a curved path

If Earth's mass decreased to one half its original mass, with no change in radius, the your weight would... a) stay the same b) decrease to one half your original weight c) decrease to one quarter your original weight d) none of the above

b) decrease to one half you original weight

Earth tides in which the solids surface of Earth rises and falls are caused by... a) many volcanic eruptions b) different forces between the moon and opposite parts of Earth c) the alignment of the sun and the moon d) the motion of water caused by ocean tides e) none of the above- the solid surface of Earth cannot have tides

b) different forced between the moon and opposite parts of Earth

According to Newton's laws, a rock and a pebble will fall with the same acceleration in a gravitational field because the gravitational force on each is... a) the same b) different, though the ratio of the force to the mass of each is the same c) none of the above

b) different, though the ratio of the force to the mass of each is the same

A supplier wants to make a profit by buying metal by weight at one altitude and selling it at the same price per pound at another altitude. The supplier should... a) but at a low altitude and sell at a high altitude b) disregard altitude because it has a negligible effect c) buy at a high altitude and sell at low altitude

b) disregard altitude because it has a negligible effect

An object is placed exactly halfway between Earth and the moon. The object will fall toward.. a) the moon b) earth c) neither earth not the moon

b) earth

The force of gravity does work on a satellite when it is in... a) circular orbit b) elliptical orbit c) both A and B d) neither A nor B

b) elliptical orbit

A vertically oriented rocket that maintains a continuous upward velocity of 8 km/s will... a) not be able to escape earth b) escape earth

b) escape earth

During an eclipse of the sun, when the moon comes between the sun and Earth, the ocean tide nearest the moon would be... a) extra low b) extra high c) both A and B d) the same as always

b) extra high

If the radius of Earth decreased, with no change in mass, your weight would... a) decrease b) increase c) not change

b) increase

If the radius of Earth decreased, with no change in mass, your weight would... a) not change b) increase c) decrease

b) increase

Compared to the period of a satellite in orbit close to earth, the period of a satellite in orbit far from earth is... a) the same b) longer c) shorter d) not enough enformation

b) longer

The speed of a satellite in an elliptical orbit is... a) independent if the height if the satellite b) not constant c) constant

b) not constant

If you stood atop a ladder on Earth that was as tall as Earth's radius (so you were twice as far from Earth's center) your weight atop the ladder would be... a) one-eighth its normal value b) one-quarter its normal value c) half its normal value d) none of the abo

b) one-quarter its normal value

In order for tidal forces to be significant, there must be a relatively large distance between... a) the body causing tides and the body experiencing tides b) opposite sides of the body experiencing tides c) both A and B d) none of the above

b) opposite sides of the body experiencing tides

When a star collapses to form a black hole, its mass... a) decreases b) remains the same c) increases

b) remains the same

Compared to the gravitational field on the surface of Earth, the gravitational field well below earth's surface is... a) larger b) smaller c) the same

b) smaller

Each of us weighs a tiny bit less on the ground floor of a skyscraper than we do on the top floor. One reason for this is that... a) the gravitational field is shielded inside the building b) the mass of the building attracts you upward slightly c) both A and B d) none of the above

b) the mass of the building attracts you upward slightly

The reason the moon does not fall into Earth is that... a) Earth's gravitational field at the moon is weak b) the moon has a sufficiently large orbital speed c) gravitational pull of other planets keeps the moon up d) the moon has less mass than Earth e) none of the above

b) the moon has a sufficiently large orbital speed

Th effect of the sun's pull on Earth's oceans is much less visible than that of the moon's pull because... a) earth is spinning so fast b) the sun is so far away c) earth is orbiting so fast d) the sun is radiating a lot of energy e) none of the above

b) the sun is so far away

An object dropped from rest almost infinitely far from Earth falls to Earth because of Earth's gravitational field, and strikes the surface with a speed of about... a) 8 km/s b) 9.8 km/s c) 11 km/s d) none of the above

c) 11 km/s

Escape speed from the surface of Earth is about... a) 8 km/s b) 9.8 km/s c) 11.2 km/s d) 16 km/s e) it is impossible to completely escape from Earth

c) 11.2 km/s

How many high tides are there normally each day on a typical ocean beach? a) 0 b) 1 c) 2 d) 4

c) 2

The curvature of Earth is such that for every 8000 m tangent to the surface, the surface drops about... a) 0m b) 2.5m c) 5m d) 10m e) 20m

c) 5m

The orbital speed for a satellite orbiting very close to Earth's surface is... a) 1600 m/s b) 4900m/s c) 8000 m/s d) 16,000 m/s e) 80,000 m/s

c) 8000 m/s

A lunar eclipse happens when... a) the moon is between Earth and the sun b) the sun is between Earth and the moon c) Earth is between the moon and the sun

c) Earth is between the moon and the sun

Which is greater, the gravitational force between Earth and the moon, or the force between Earth and the sun? a) Earth-moon b) equal c) Earth-sun

c) Earth-sun

A circle is a special case of... a) a hyperbola b) a parabola c) an ellipse d) a focus

c) an ellipse

The reason satellites orbit Earth at least 150 km above the surface is to... a) be above Earth's gravity b) make sure they are higher than the highest mountains c) be above Earth's atmosphere d) keep them out of the way of commercial airliners e) all of the above

c) be above Earth's atmosphere

Pluto takes a longer time to travel around the sun than Earth takes because Pluto... a) has further to go b) goes slower c) both a and b d) none of the above

c) both a and b

A very massive object A and a less massive object B move toward each other under the influence of mutual gravitation. Which force, if either, is greater? a) the force on B b) the force on A c) both forces are the same

c) both forced are the same

Newton had the insight to see that the... a) moon is moving b) moon orbits earth c) force on the moon has the same nature as the force on an apple d) moon always keeps one side toward earth e) none of the above

c) force on the moon had the same nature as the force on an apple

Gravitational forces are the weakest forces found in nature. Because of this... a) the gravitational effect between pencil and Earth cannot be seen b) there is no gravitational force between two 1-kg masses c) gravitational forces that are easily observed involve one or more large masses d) there is no movement between two 1-kg masses located near each other in space e) gravitational effects occur only when a large mass is involved

c) gravitational forces that are easily observed involve one or more large masses

If the mass if Earth increased, with no change in radius, your weight would... a) stay the same b) decrease c) increase also

c) increase also

Two objects move toward each other because of gravitational attraction. As the objects get closer and closer, the force between them... a) remains constant b) decreases c) increases

c) increases

What remains constant for a satellite in an elliptical orbit? a) its speed b) Its potential energy c) its total energy d) its kinetic energy e) its distance from the planet

c) its total energy

Jupiter has more than 300 times the mass of Earth. Yet on Jupiter's surface on object weighs only about 3 times as much as it would on Earth. The explanation to this involves Jupiter's... a) high density b) greater distance from the sun c) large radius

c) large radius

A lunar month is about 28 days. If the moon were closer to Earth than it is now, the lunar month would be... a) more than 28 days b) unchanged at 28 days c) less than 28 days

c) less than 28 days

A hollow spherical planet is inhabited by people who live inside it, where the gravitational is zero. When a very massive space ship lands on the planet's surface, the gravitational field inside the planet is... a) nonzero, directed away from the spaceship b) still zero c) nonzero, directed toward the spaceship

c) nonzero, directed toward the spaceship

Ocean tides occur mainly because... a) of the gravitational pull of the sun on Earth b) water normally runs to the side of Earth away form the sun c) of different gravitational pulls of the moon on opposite sides of Earth d) as Earth rotates it leaves the ocean water somewhat behind it e) none of the above

c) of different gravitational pulls of the moon on opposite sides of Earth

The force of gravity on you is greatest when you are standing... a) far above Earth's surface b) just above Earth's surface c) on Earth's surface

c) on Earth's surface

If the sun were to collapse to form a black whole (quite unlikely), Earth would... a) immediately disappear b) spiral into the black hole c) orbit the black hole just as it orbits the sun now d) leave the solar system in the direction of its tangential velocity e) be drawn into the black hole

c) orbit the black hole just as it orbits the sun now

Which produces a greater tidal effect in your body, the moon of a 1-kg melon that you hold above you head? a) not enough information given to make a reasonable estimate b) the moon c) the melon

c) the melon

A period of a satellite is defined as... a) the time for a satellite to cross the United States b) 1 second c) the time for a satellite to make one complete revolution around Earth d) 90 seconds e) 24 hours

c) the time for a satellite to make on complete revolution around Earth

Suppose the moon were covered with water and orbited Earth as it now does. In that case the moon would have... a) four tidal bulges b) no tidal bulges c) two tidal bulges d) one tidal bulge e) three tidal bulges

c) two tidal bulges

The gravitational field strength at the center of Earth is... a) the same as on the surface b) smaller than on the surface but still larger than zero c) zero d) large

c) zero

By noticing that Uranus's orbit is perturbed and by using the law of gravitation, two astronomers independently discovered... a) Neptune b) exceptions to the law of gravity c) the law of gravitation fails at large distances d) Uranus has several moons

d) Uranus has several moons

The circular orbit of a satellite orbiting Earth is characterized by a constant... a) speed b) radius c) magnitude of acceleration d) all of the above e) none of the above

d) all of the above

The gravitational force between two massive spheres... a) is always an attraction b) depends on how massive they are c) depends inversely on the square of the distances between them d) all of the above

d) all of the above

There would still be two ocean tides per 24 hours if... a) the sun's influences on the tides were negligible b) Earth and mood had equal masses c) the moon had more mass than Earth d) any of the above e) none of the above

d) any of the above

Where does a satellite in a circular orbit have the greatest kinetic energy? a) at the point farthest from the planet b) exactly at the point halfway to the planet c) at the point closest to the planet d) anywhere- its kinetic energy is constant e) more information is needed

d) anywhere- its kinetic energy is constant

The higher satellite is, the... a) less its speed is b) greater its speed is c) longer its period is d) both A and C e) both B and C

d) both A and C

The fastest moving planet in a solar system is... a) the most massive planet b) any planet (they all move at the same speed) c) the smallest planet d) the planet nearest the sun

d) the planet nearest the sun

If you were to weigh yourself in an elevator that is accelerating upward, compared to your ordinary weight, you would weigh... a) more b) the same c) less, but more than zero d) zero

d) zero

Suppose the gravitational force between two massive spheres is 100 N. If the distance between the spheres is doubled, what is the force between the masses? a) 400 N b) 200 N c) 100 N d) 50 N e) 25 N

e) 25 N

A black hole is an object that... a) alters the space around it b) has an enormous density c) has an enormous gravitational field near it d) has an escape speed greater than the speed of light e) all of the above

e) all of the above

Gravitational field lines show the... a) direction of the field at each point b) direction of the force on any mass c) direction a mass would be accelerated d) strength of the field e) all of the above

e) all of the above

Newton hypothesized that the moon... a) is a projectile b) is falling around Earth c) has a tangential velocity that prevents it from falling into Earth d) is actually attracted to Earth e) all of the above

e) all of the above

The value of the acceleration due to gravity,g,... a) depends on the universal gravitational constant, G b) depends on the mass of Earth c) is different on different planets d) depends on the radius of Earth e) all of the above

e) all of the above

We can tell if a gravitational force exists in a region of space if... a) we disturb a pendulum and it starts swinging b) we let go of a ball and it starts to move c) a force exists on a mass placed there d) we can weigh ourselves e) all of the above

e) all of the above

Suppose the moon had twice its present mass and still orbited earth at the same distance. In that case... a) the ocean tide facing the moon would rise, and the other tide would lower b) the ocean tides would be the same as they are now c) both ocean tides would be smaller d) the ocean tide facing the moon would lower, and the other tide would rise e) both ocean tides would be higher

e) both ocean tides would be higher