FINAL: CH4

Question 1

Newton discovered:

Answer 1

that gravity is universal

Question 2

What is the force of gravity on a 500N woman standing on Earth's surface?
A.) 50 N
B.) 250 N
C.) 500 N 
D.) 598 N
E.) 5000 N

Answer 2

C.) 500 N

The gravity force on the woman is the same as the woman on the gravity force.

Question 3

A very massive object A and a less massive object B move toward each other under the influence of gravity. Which force, if either, is greater?

Answer 3

C.) both forces are the same

Question 4

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

Answer 4

Earth

Question 5

The force of gravity acts on all apples on an apple tree. Some apples are twice as far from the ground. Such twice-as-high apples of the same mass have
A.) 1/4 the weight
B.) 1/2 the weight
C.) practically the same weight

Answer 5

C.) practically the same weight

Question 6

In the vacuum of outer space, there is no:

Answer 6

atmospheric pressure

Question 7

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 because the
A.) gravitational force is shielded inside the building
B.) mass of the building attracts us upward slightly
C.) both
D.) none of the above

Answer 7

B.) mass of the building attracts us upward slightly

Question 8

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 cant travel far enough

Answer 8

D.) forget it; you can’t travel far enough

Question 9

Inside a freely falling elevator you would experience no
A.) gravitational force
B.) weight
C.) both
D.) none of the above

Answer 9

B.) weight

Question 10

The sun is spherical due to
A.) Earth circling it
B.) Earth and Moon circling it
C.) gravitation
D.) none of the above

Answer 10

C.) gravitation

Question 11

The planet Neptune was discovered by perturbations of 
A.)  Uranus
B.) its moon
C.) Pluto
D.) none of the above
E.

Answer 11

A.) Uranus

Question 12

A bullet fired from a rifle begins to fall
A.) as soon as it leaves the barrel
B.) after air friction reduces its speed
C.) neither

Answer 12

A.) as soon as it leave the barrel

Question 13

A stone is thrown horizontally from the top of a cliff. One second after leaving your hand it drops a vertical distance of
A.) 5m
B.) 10m
C.) 15m

Answer 13

A.) 5m

Question 14

A gun with a muzzle velocity of 100 m/s is fired horizontally from a tower. Neglecting air resistance, how far downrage will the bullet be 1s later?
A.) 50m
B.) 98m
C.) 100m
D.) 500m
E.) none of the above

Answer 14

C.) 100m

Question 15

A projectile is launched at an angle of 15 degrees above the horizontal and lands downrange. With no air resistance, what other projection angle for the same speed would produce the same downrage distance?
A.) 30 degrees
B.) 45 degrees
C.) 50 degrees
D.) 75 degrees
E.) 90 degrees

Answer 15

D.) 75 degrees

Question 16

A projectile is fired vertically from the surface of the Earth at 8km/s and remains in a vertical path. The projectile will
A.) go into circular motion about Earth.
B.) Rise and fall back to Earth’s surface
C.) follow an uncertain path

Answer 16

B.) rise and fall back to Earth’s surface

Question 17

Earth’s satellites are typically more than 100-km high so as to mainly be above the Earth’s
A.) atmosphere
B.) gravitational influence
C.) both

Answer 17

A.) atmosphere

Question 18

Compared with the period of satellites in orbit close to Earth, the period of satellites in orbit far from Earth is 
A.) longer
B.) shorter
C.) the same
D.) not enough information

Answer 18

A.) longer

Question 19

The fastest moving planet in a solar system is
A.) the smallest planet
B.) the most massive planet
C.) the planet nearest the sun
D.) the planet farthest from the sun
E.) any planet, for they all move at the same speed.

Answer 19

C.) the planet nearest the sun

Question 20

The planet 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

Answer 20

C.) both

Question 21

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

Answer 21

C.) orbiting Earth with a 24-hour period

Question 22

A satellite in an elliptical orbit travels at constant
A.) velocity
B.) speed
C.) acceleration
D.) all of the above
E.) none of the above

Answer 22

E.) none of the above

Question 23

The force of gravity does work on a satellite when it is in
A.) circular orbit
B.) elliptical orbit
C.) both
D.) neither

Answer 23

B.) elliptical orbit

Question 24

Escape speed from Earth is
A.) 8 km/s
B.) 9.8 km/s
C.) 11.2 km/s
D.) 42.2 km/s

Answer 24

C.) 11.2 km/s

Question 25

``` If the masses of two planets doubled and the distance between them also doubles, the force between them could be: A.) one-quarter B.) half as much C.) twice as much D.) four times as much E.) none of the above ```

Answer 25

E.) none of the above

Question 26

``` A woman who normally weighs 400N stands on top of a very tall ladder so she is one Earth-radius above Earth's surface. What is her weight there? A.) zero B.) 100N C.) 200N D.) 400N E.) none of the above ```

Answer 26

B.) 100N

Question 27

The amount of gravitational force that acts on a space vehicle that orbits Earth is A.) nearly zero B.) nearly as much as the vehicles weight on Earth. C.) the same as the vehicles weight on Earth.

Answer 27

B.) nearly as much as the vehicles weight on Earth.

Question 28

The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much. This is because A.) your mass is 100 times less on Jupiter B.) Jupiter is significantly farther from the Sun. C.) Jupiter's radius is 10 times Earth's radius D.) you are 100 times more weightless there. E.) none of the above

Answer 28

C.) Jupiter's radius is 10 times Earth's radius

Question 29

A projectile is launched straight upward at 50 m/s. If air resistance is negligible, its speed upon returning to its starting point is A.) less than 50 m/s B.) 50 m/s C.) more than 50 m/s

Answer 29

B.) 50 m/s

Question 30

Without air resistance, a projectile fired horizontally at 8 km/s from a mountaintop will A.) accelerate downward at g as it moves horizontally B.) trace a curve that matches Earth's surface C.) return to its starting position and repeat falling behavior. D.) all of the above E.) none of the above

Answer 30

D.) all of the above

Question 31

``` A satellite near Earth makes a full circle in about 90 minutes. How long would a satellite located as far as the Moon take to orbit Earth? A.) 90 minutes B.) less than 90 minutes C.) about 28 days D.) not enough information E.) none of the above ```

Answer 31

C.) about 28 days