Physical Science - Homework 6

Escape speed from earth is

11.2 km/s

A woman who normally weighs 800 N stands on top of a very tall ladder so she is one Earth radius above earth's surface. What is her weight there?

200 N

What is the force of gravity on a 400 N woman standing on Earth's surface?

400 N

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

If the mass of Earth somehow decreased with no change in radius, your weight would a. increase b. decrease c. remains the same

b. decrease

A rock is thrown upward 50° with respect to the horizontal. As it rises, it's vertical component of velocity a. stays the same b. decreases c. increases

b. decreases

Two objects move toward each other due to gravity. As the objects get closer and closer, their accelerations a. decrease b. increase c. remain constant

b. increase

Inside a freely falling elevator your a. acceleration is zero b. measured weight is zero c. gravitational interaction with earth is zero d. all of the above e. none of the above

b. measured weight is zero

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

earth

The planet Neptune was discovered by perturbations of a. Uranus b. it's moon c. Pluto d. none of the above

a. Uranus

The international space station orbits at an average 360 km altitude so that it is mainly above earth's a. atmosphere b. gravitation c. both

a. atmosphere

According to Newton, the greater the masses of interacting objects, the a. greater the gravitational force between them b. less the gravitational force between them c. greater the distance between them d. B and C only

a. greater the gravitational force between them

An earth satellite is in an elliptical orbit. The satellite travels fastest when it is a. nearest the earth b. farthest from the earth c. neither

a. nearest the earth

The tangential velocity of a satellite orbiting earth is velocity a. parallel to the surface of the earth b. perpendicular to the surface of the earth c. attributed to satellites moving in any direction d. none of these

a. parallel to the surface of the earth

A hunter aims a rifle at an angle of 10° above the horizontal. The hunger fires a bullet while simultaneously dropping another bullet from the side of the rifle. Which bullet hits the ground first? a. the dropped one b. the fired one c. both hit at the same time

a. the dropped one

According to Newton, the greater the distance is between gravitationally interacting objects a. the lower is the gravitational force between them b. the greater is the gravitational force between them c. greater is the likelihood that the force between them remains constant

a. the lower is the gravitational force between them

Planets would crash into the Sun if it weren't for a. their tangential velocities b. their vast distances from the sun c. the inverse-square law d. their relatively small masses e. the fact that they're beyond the main gravitation of the sun

a. their tangential velocities

A projectile is fired horizontally. With no air resistance, it maintains its horizontal component of velocity because a. no force acts on it b. no horizontal forces act on it c. of no initial vertical component of velocity d. all of the above e. none of the above

b. no horizontal forces act on it

Roll a golf ball off the edge of a table. As it falls, it's horizontal component of motion a. decreases b. remains constant c. increases

b. remains constant

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 a. less b. the same c. more

b. the same

Jupiter takes a longer time to travel around the Sun than Earth because Jupiter a. has farther to go b. goes slower c. both d. none of the above

c. both

A hunger fires a bullet from a horizontally held rifle while simultaneously dropping another bullet from the side of the rifle. Which bullet hits the ground first? a. the dropped one b. the fired one c. both hit at the same time

c. both hit at the same time

The Sun is spherical due to a. it's nuclear reactions b. the planet is circling it c. gravitation d. none of the above

c. gravitation

Communications and weather satellites always appear at the same place in the sky because these satellites are a. beyond the pull of Earth's gravitational field b. moving at a speed just short of escape velocity c. orbiting earth with a 24 hour period d. stationary in space e. none of the above

c. orbiting earth with a 24 hour period

A ball is thrown upwards and caught when it returns. Neglecting air resistance, the speed with which it is caught is a. less than it's initial speed b. more than it's initial speed c. the same as it's initial speed

c. the same as it's initial speed

The more massive Earth attracts the Moon with a. greater force than the force with which the moon attracts the earth b. less force than the force with which the moon attracts the earth c. the same force as that which with the moon attracts the earth

c. the same force as that which the moons attracts the earth

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 a. one quarter b. half as much c. twice as much d. four times as much e. sixteen times as much

c. twice as much

The circular orbit of a satellite orbiting the earth is characterized by a constant a. radial distance b. acceleration magnitude c. speed d. all of these e. none of these

d. all of these

If earth's radius were doubled, your weight would a. increase b. double c. decrease to 1/2 it's value d. decrease to 1/4 it's value e. quadruple

d. decrease to 1/4 it's value

How far must one travel to completely be beyond earth's gravity? a. to a region above the earth's atmosphere b. to a region well beyond the moon c. to a region beyond the solar system d. forget it; you can't travel far enough

d. forget it; you can't travel far enough