1. A heavy crate falls from a high
flying airplane just as it flies directly above a shiny
Black Lexus parked in a car lot. The plane moves in the
leftward direction. Relative to the Lexus, where will the crate
crash? |
a. on top the Lexus |
b. at a point to the left of the
Lexus |
c. at a point to the right of
the Lexus |
d nota |
2. In the previous problem, if the
airplane flies 50.0 m high, how long does it take the crate to hit
the ground? Choose the closest answer to your computation. |
a. 2.3 seconds |
b. 3.2 seconds |
c. 1.0 second |
3. Suppose the airplane in the previous problem
was flying at 30.0 m/s. Where does the crate land? |
a. on top of the Lexus |
b. about 96 m from the Lexus |
c. about 69 m from the
Lexus |
4. In the absence of air resistance,
the horizontal component VH of a projectile is
|
a. constant |
b. is not constant
|
5. True or False. If you fire a
rifle at a distant target at the same vertical height as the gun,
to hit the target you should aim exactly at the target.
|
a. True |
b. False |
6. A projectile is fired straight
upward with speed 1000 m/s . What is the speed when the projectile
reaches the top of the trajectory? |
a. 1000 m/s |
b. 100 m/s |
c. nota |
7. A projectile is fired with
speed 1410 m/s at an angle of 45 0 with the horizontal.
What is the horizontal component VH of the projectile?
|
a.1000 m/s |
b.100 m/s |
c. 0 m/s |
8. A NASA spacecraft orbits
closely in a circle around the Moon. The orbital speed is
|
a. greater than 8 km/s
|
b. less than 8 km/s
|
c. equal to 8 km/s
|
d. nota |
9. What will be the speed of a
spacecraft in close circular orbit around a 20 m asteroid?
|
a. greater than 8 km/s
|
b. equal to 8 km/s
|
c. nota |
10. True or False. If a
satellite moves in a circular orbit, during its motion its kinetic
energy changes.
|
a. True |
b. False |
11. True or False. If a
satellite moves in an elliptical orbit, during its motion its kinetic
energy does not change. |
a. True |
b. False |
12. True or False. If a
satellite moves in an elliptical orbit, during its motion its potential
energy does not change. |
a. True |
b. False |
13. A satellite moves in an
elliptical orbit around a planet. During its motion, its kinetic
energy is greatest |
a. at a point nearest the planet |
b. at a point farthest away from the
planet |
c. kinetic energy does not
change |
14. A satellite moves in an
elliptical orbit around a planet. During its motion, its potential
energy is greatest |
a. at a point nearest the planet |
b. potential energy does not
change |
c. nota |
In
the next two problems below, a
projectile is fired
horizontally with speed V and from height h above the ground.
No air resistance. |
15. The
formula for the vertical height is |
a.
h = gt |
b.
h = (1/2)*gt2. |
c.
nota |
16.
The formula for the horizontal distance
D traveled is |
a.
D = g*t |
b.
D = V*t |
17. What is the
formula for the magnitude F of the attractive force between two point
masses m and M a distance D from each other? |
18. Two
planets are separated by a distance D and the magnitude of the
force of attraction between them is F. If the distance between the
planets is increased by a factor of 2, the magnitude of the force of
attraction will be |
a. 4F |
b. F/4 |
c. F/8 |
d. F/16 |