Download Lesson 4.04 and 4.05 Self

Lesson 4.04 Newton’s Law of Gravity
Lesson 4.05 Orbits of Planets and Satellites
Self-Check Quiz
1. Two bodies, masses m1 and m2, are at distance r from each other and
attract each other with force F. Find the gravitational force if the
distance is doubled.
a. 2F
b. F/2
c. F/4
d. 4F
Answer: _____
2. The weight of a 0.5 kg object on the surface of Planet X is 20 N. If
the radius of the planet is 4 X 106 m, what is its mass?
a. 3.4 X 1019 kg
b. 2.6 X 1022 kg
c. 9.6 X 1024 kg
d. 2.3 X 1025 kg
Answer: _____
3. How far from the center of the Earth is the point where the net
force of the gravitational attraction of the Earth and the moon is
zero? The mass of the moon is 1/81 that of the Earth.
a. 8/9 the way to the moon
b. 9/10 the way to the moon
c. 3/4 the way to the moon
d. 80/81 the way to the moon
Answer: _____
4. The radius of Planet Z is 3 times the radius of the Earth. It has
the same density as the Earth. What is the gravitational acceleration
at the surface of the planet?
a. 29.4 m/s2
b. 88.2 m/s2
c. 265 m/s2
d. 3.27 m/s2
Answer: _____
5. Use Kepler's Law to find the time (in Earth's years) for Mars to
orbit the sun if the radius of Mars' orbit is 1.5 times the radius of
Earth's orbit.
a. 1.8
b. 2.8
c. 3.4
d. 4.2
Answer: _____
6. The mass of Mars is about 1/10 the mass of Earth. Its diameter is
about 1/2 the diameter of Earth. What is the gravitational acceleration
at the surface of Mars?
a. 9.8 m/s2
b. 2.0 m/s2
c. 3.9 m/s2
d. 4.9 m/s2
e. none of these
Answer: _____
7. The mass of Planet W is 1/100 that of Earth and its radius is 1/4
that of Earth. If the weight of an object is 600 N on Earth, what would
it weigh on Planet W?
a. 24 N
b. 48 N
c. 96 N
d. 192 N
e. 600 N
Answer: _____
8. The weight of an object at the surface of Earth is 90 N. What is its
weight at a distance 2R from the surface of Earth?
a. 10 N
b. 30 N
c. 90 N
d. 270 N
e. 810 N
Answer: _____
9. The periods of a satellite orbiting a planet does not depend on the:
a. radius of the orbit
b. mass of the planet
c. mass of the satellite
d. it depends on all of the above
Answer: _____
10. A 9.0 × 10 3 kg satellite orbits the earth at the distance of 2.56 ×
10 7 m from Earth's surface. What is its period?
a. 1.1× 10
b. 4.1 × 10 4 s
c. 5.7 × 10 4 s
d. 1.5 × 10 5 s
4
s
Answer: _____
11. A missile is launched upward with a speed that is half the escape
speed. What height (in radii of Earth) will it reach?
a. R/4
b. R/3
c. R/2
d. R
e. 2R
Answer: _____
12. The weight of a 0.6 kg object at the surface of Planet V is 20 N.
The radius of the planet is 4 X 106 m. Find the gravitational
acceleration at a distance of 2.0 X 106 m from the surface of this
planet.
a. 9 m/s2
b. 11 m/s2
c. 13 m/s2
d. 18 m/s2
Answer: _____