Ch 4 - test 2

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 weigh there? zero 100 N 200 N 400 N none of the above

100 N

A projectile is launched upward at an angle of 75 ∘ ° from the horizontal and strikes the ground a certain distance downrange. At what other angle of launch at the same speed would this projectile land just as far away?

15 degrees

Two projectiles are fired at equal speeds but different angles. One is fired at an angle of 30° and the other at 60°. With no air resistance, the projectile to hit the ground first will be the one fired at 60°. 30°. both hit at the same time

30

What is the magnitude of the gravitational force between Earth and a 1- kg body at its surface?

9.8 N

Using the formula for gravity, find the force of gravity on a 1.1- kg mass at Earth's surface. (The mass of Earth is 6× 10 24 kg , and its radius is 6.4× 10 6 m .).

F = 11N

Find the force of gravity between Earth (mass = 6.0× 10 24 kg ) and the Moon (mass = 7.4× 10 22 kg ). The average Earth-Moon distance is 3.8× 10 8 m .

F = 2.1 x 10^20 N

If the Sun were twice as massive, its pull on the Earth would double. Earth's pull on the Sun would double. both neither

both

If your mass remained the same while the mass of Earth doubled while staying the same size, your weight would be eight times as much as now. double. be the same. quadruple. none of the above

double.

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

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 masses. less the gravitational force between them. greater the gravitational force between them.

greater the gravitational force between them.

An airplane is flying horizontally with speed 1300 km/h (360m/s) when an engine falls off. Neglecting air resistance, assume it takes 29 s for the engine to hit the ground. Find the altitude of the airplane. (Use g=9.8m/s2.) Find the horizontal distance the airplane engine falls. If the airplane somehow continues to fly as if nothing had happened, where is the engine relative to the airplane at the moment the engine hits the ground? The engine is directly below the airplane. The engine is before the airplane. The engine is behind the airplane.

h=4.1 km d= 10 km The engine is directly below the airplane.

According to Newton, the greater the distance between gravitationally interacting objects, the constancy of the force between them. more the gravitational force between them. less the gravitational force between them.

less the gravitational force between them.

Consider a space pod somewhere between Earth and the Moon, at just the right distance so that the gravitational attractions to Earth and the Moon are equal. Is this location nearer Earth or the Moon?

nearer the moon

Consider a space probe three times as far from Earth's center as it would be at Earth's surface. Compared to at Earth's surface, its gravitational attraction to Earth at this distance is about _______. View Available Hint(s) one-ninth as much zero one-half as much one-third as much

one-ninth as much

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

remains constant.

Newton discovered that gravity is universal. gravity. neither

that gravity is universal.

Consider Earth and the Moon. As you should now realize, the gravitational force that Earth exerts on the Moon is equal and opposite to that which the Moon exerts on Earth. Therefore, according to Newton's second law of motion __________. View Available Hint(s) the Moon has a larger acceleration than Earth, because it has a smaller mass Earth has a larger acceleration than the Moon, because it has a larger mass the Moon and Earth both have equal accelerations, because the forces are equal

the Moon has a larger acceleration than Earth, because it has a smaller mass

A "weightless" astronaut in an orbiting space vehicle is shielded from Earth's gravitational effects. without a support force. beyond the pull of gravity. all of the above none of the above

without a support force.