EDS 1031 Sec1 Chapter 4

Pioneer 10 was able to escape the solar system by "bouncing off" Jupiter like a tennis ball bouncing off an approaching tennis racket. having a sufficient escape velocity at launch. nuclear-powered sustained thrust. refueling via solar cells.

"bouncing off" jupiter like a tennis ball bouncing off an approaching tennis racket

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

11.2 km/s

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 25 m/s 5 m/s 10 m/s none of the above

20m/s

A ball is thrown horizontally from the top of a tall cliff. Three seconds later, the ball has fallen a vertical distance of 20 m. depends on the initial horizontal speed of the ball 30 m. 45 m.

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. 15 m. 10 m.

5m

The hang time of an athlete who moves horizontally 2.0 m during a 1.25-m-high jump is about 1 s. less than 1 s. more than 1 s.

about 1s

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. less than 90 minutes. 90 minutes. not enough information none of the above

about 28 days

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

atmospheric pressure

If the Sun were twice as massive, Earth's pull on the Sun would double. its pull on the Earth would double. both of these none of the above

both of these

If Earth's mass somehow decreased with no change in its radius, your weight would increase. decrease also. remain the same.

decrease also

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

decreases

An Earth satellite in an elliptical orbit travels slowest when it is nearest the Earth. farthest from the Earth. neither of these

farthest from the earth

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

forget it; you can't travel far enough

According to Newton, the greater the masses of interacting objects, the greater the force between them by the square of the distance. greater the force between them by the square of the masses. less the gravitational force between them. greater the gravitational force between them.

greater the gravitational force between them

If the radius of the Earth somehow decreased with no change in mass, your weight would not change. decrease. increase.

increase

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

increases

Perturbations of planets are due to deviations from straight-line paths. uneven masses of planets. interplanetary forces. none of the above

interplanetary forces

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

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 greater than 8 km/s. less than 8 km/s. about 8 km/s.

less than 8km/s

The force of gravity on a satellite in circular orbit doesn't change its speed because the force is canceled by centrifugal force. small compared to other forces on it. very weak due to altitude. perpendicular to its direction of motion.

perpendicular to its direction of motion

The radial velocity of an Earth satellite is its velocity attributed to satellites moving in any direction. perpendicular to the surface of Earth. parallel to the surface of Earth. none of the above

perpendicular to the surface of earth

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

remains constant

A projectile that is fired vertically at 5 km/s from the Earth's surface will go into a circular orbit about Earth. rise and fall back to Earth's surface. go into an elliptical orbit about Earth. none of the above

rise and fall back to earth's surface

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. the fired one. both hit at the same time

the dropped one

The Moon does not crash into Earth because Earth's gravitational field is weak at the Moon's distance. the gravitational pull of other planets keeps the Moon up. the Moon has less mass than Earth. the Moon has a sufficient tangential speed. none of the above

the moon has a sufficient tangential speed

The planet Neptune was discovered by perturbations of its moons. Uranus. Pluto. none of the above

uranus

Inside a freely-falling elevator your gravitational interaction with Earth is zero. acceleration is zero. weight is zero. all the above none of the above

weight is zero

Strictly speaking, when you step off a curb you are momentarily weightless. in orbit. in space.

weightless