Physics

# Multiple Choice

PhysicsMultiple Choice

### 7.1Kepler's Laws of Planetary Motion

20.

A planet of mass m circles a sun of mass M. Which distance changes throughout the planet’s orbit?

1. $f 1 f 2 ¯ f 1 f 2 ¯$
2. $m M ¯ m M ¯$
3. $M f 2 ¯ M f 2 ¯$
4. $M f 1 ¯ M f 1 ¯$
21.
The focal point of the elliptical orbit of a moon is $50 comma 000 km$ from the center of the orbit. If the eccentricity of the orbit is $0.25$, what is the length of the semi-major axis?
1. $12 comma 500 km$
2. $100 comma 000 km$
3. $200 comma 000 km$
4. $400 comma 000 km$
22.

An artificial satellite orbits the Earth at a distance of 1.45×104 km from Earth’s center. The moon orbits the Earth at a distance of 3.84×105 km once every 27.3 days. How long does it take the satellite to orbit the Earth?

1. 0.200 days
2. 3.07 days
3. 243 days
4. 3721 days
23.

Earth is 1.496×108 km from the sun, and Venus is 1.08×108 km from the sun. One day on Venus is 243 Earth days long. What best represents the number of Venusian days in a Venusian year?

1. 0.78 days
2. 0.92 days
3. 1.08 days
4. 1.21 days

### 7.2Newton's Law of Universal Gravitation and Einstein's Theory of General Relativity

24.

What did the Cavendish experiment measure?

1. The mass of Earth
2. The gravitational constant
3. Acceleration due to gravity
4. The eccentricity of Earth’s orbit
25.
You have a mass of $55 kg$ and you have just landed on one of the moons of Jupiter where you have a weight of $67.9 upper N$. What is the acceleration due to gravity, $g$, on the moon you are visiting?
1. $0.810 m slash s squared$
2. $1.23 m slash s squared$
3. $539 m slash s squared$
4. $3735 m slash s squared$
26.
A person is in an elevator that suddenly begins to descend. The person knows, intuitively, that the feeling of suddenly becoming lighter is because the elevator is accelerating downward. What other change would produce the same feeling? How does this demonstrate Einstein’s postulate on which he based the theory of general relativity?
1. It would feel the same if the force of gravity suddenly became weaker. This illustrates Einstein’s postulates that gravity and acceleration are indistinguishable.
2. It would feel the same if the force of gravity suddenly became stronger. This illustrates Einstein’s postulates that gravity and acceleration are indistinguishable.
3. It would feel the same if the force of gravity suddenly became weaker. This illustrates Einstein’s postulates that gravity and acceleration are distinguishable.
4. It would feel the same if the force of gravity suddenly became stronger. This illustrates Einstein’s postulates that gravity and acceleration are distinguishable.