1. According to Kepler’s second law, a planet sweeps out equal areas in
A.
equal intervals of time
B.
equal distances from the Sun
C.
equal angular distances
D.
equal intervals of distance
Correct Answer:
equal intervals of time
Explanation:
Kepler’s second law states that the line joining a planet and the Sun sweeps out equal areas in equal intervals of time.
2. If a planet sweeps out an area of 5 square units in 2 days, what area will it sweep out in the next 2 days?
A.
2.5 square units
B.
5 square units
C.
10 square units
D.
20 square units
Correct Answer:
5 square units
Explanation:
Equal time intervals correspond to equal swept areas, so the next 2-day interval also gives an area of 5 square units.
3. In equal time intervals, the area swept by the line joining a planet to the Sun is
A.
always equal
B.
always zero
C.
always increasing
D.
always decreasing
Correct Answer:
always equal
Explanation:
Kepler’s second law directly states that equal areas are swept in equal time intervals.
4. A planet moves closer to the Sun during one part of its orbit. During equal time intervals, its speed is
A.
greater when it is closer to the Sun
B.
smaller when it is closer to the Sun
C.
zero when it is closer to the Sun
D.
the same at every point in the orbit
Correct Answer:
greater when it is closer to the Sun
Explanation:
To sweep equal areas in equal times, the planet must move faster when it is closer to the Sun and slower when it is farther away.
5. If a planet sweeps 12 square units in 3 hours, its area swept in 1 hour is
A.
3 square units
B.
4 square units
C.
9 square units
D.
36 square units
Correct Answer:
4 square units
Explanation:
Since equal time intervals sweep equal areas, the area swept per hour is 12 divided by 3, which is 4 square units.
6. Kepler’s second law is also commonly called the law of
A.
equal areas
B.
equal distances
C.
equal speeds
D.
equal periods
Correct Answer:
equal areas
Explanation:
Kepler’s second law is known as the law of equal areas because equal areas are swept in equal time intervals.
7. When a planet is farthest from the Sun, it moves
A.
slowest in its orbit
B.
fastest in its orbit
C.
with zero speed
D.
with constant speed equal to its speed near the Sun
Correct Answer:
slowest in its orbit
Explanation:
The planet moves more slowly when far from the Sun so that it can sweep the same area during an equal time interval.
8. Two equal time intervals are considered while a planet revolves around the Sun. The areas swept in these intervals are
A.
equal, according to Kepler’s second law
B.
larger in the first interval only
C.
larger in the second interval only
D.
unrelated to each other
Correct Answer:
equal, according to Kepler’s second law
Explanation:
The defining statement of Kepler’s second law is that equal time intervals produce equal swept areas.
9. A planet covers a longer arc of its orbit in an equal time interval when it is
A.
closer to the Sun
B.
farther from the Sun
C.
at the same distance from the Sun throughout
D.
not moving around the Sun
Correct Answer:
closer to the Sun
Explanation:
The planet moves faster near the Sun, so it covers a longer orbital arc in the same time while maintaining equal swept areas.
10. If a planet sweeps equal areas in equal time intervals, its areal velocity is
A.
constant
B.
zero
C.
continuously increasing
D.
continuously decreasing
Correct Answer:
constant
Explanation:
Areal velocity is the area swept per unit time. Equal areas in equal times mean that this quantity remains constant.
Short questions are currently unavailable for this page.