9.*Force due to Gravity
9.*Gravity drops with distance
9.*Weight /weightlessness + effects of Acceleration
9.*TidesNeap TideSpring Tide
9.*-- Questions --MULTIPLE CHOICE. Choose the one alternative
that best completes the statement or answers the question.
9.*1) Consider two planets in space that gravitationally attract
each other. If the masses of both planets are doubled, and the
distance between them is also doubled, then the force between them
is one quarter. B) half as much. C) twice as much. D) four times as
much. E) none of these.
2) There are no tides to be seen in the community swimming pool
because A) it is shallow compared to the ocean. B) all parts of it
are practically the same distance from the moon. C) gravitation on
the small mass of water is negligibly small. D) they are masked by
the much stronger pull of Earth gravity. E) but there are, at
9.*3) The force of gravity acts on all apples on an apple tree.
Some apples are twice as far from the ground as others. These
twice-as-high apples, for the same mass, have A) practically the
same weight. B) 1/4 the weight. C) 1/2 the weight.
4) Newton discovered A) gravity. B) that gravity is universal.
9.*5) When the distance between two stars decreases by half, the
force between them A) stays the same. B) decreases by one-quarter.
C) decreases by one-half. D) increases to twice as much. E)
increases to four times as much.
6) The reason the moon does not crash into the Earth is that the
A) gravitational pull of other planets keeps the moon up. B) moon
has less mass than the Earth. C) Earth's gravitational field is
weak at the moon. D) moon has a sufficient tangential speed. E)
none of these.
9.*7) If the mass of the Earth somehow increased with no change
in radius, your weight would stay the same. increase also. C)
8) The factor most directly responsible for making a black hole
invisible is its A) size. B) surface escape velocity. C) mass. D)
color. E) none of these.
9.*9) According to Newton, doubling the distance between two
interacting objects A) multiplies by 4 the gravitational force
between them. B) divides by 4 the gravitational force between them.
C) divides by 2 the gravitational force between them. D) multiplies
by 2 the gravitational force between them.
10) If the moon were covered with water, tidal effects by Earth
would find the moon with A) 1 tidal bulge. B) 2 tidal bulges. C) 3
tidal bulges. D) 4 tidal bulges. E) no tidal bulges.
9.*11) Tides rise and fall A) the same distance in all parts of
the world. B) greatly different distances in different places.
12) Both Newton and Kepler considered forces on the planets.
Kepler hypothesized the direction of the forces was A) along their
directions of travel. B) toward the sun. C) neither.
9.*13) A black hole is A) an empty region of space with a huge
gravitational field. B) simply the remains of a giant star that has
undergone gravitational collapse. C) a small region that contains
the mass of many galaxies.
14) The best time for digging clams (when the low tide is extra
low) is during the time of the half moon. B) new or full moon. C)
quarter moon. D) ...none of these times in particular.
9.*15) When a star collapses to form a black hole, its mass
remains the same. increases. C) decreases.
9.*-- Answers --MULTIPLE CHOICE. The one alternative that best
completes the statement or answers the question.
1) Answer: E 2) Answer: B 3) Answer: A 4) Answer: B 5) Answer: E
6) Answer: D 7) Answer: B 8) Answer: B 9) Answer: B 10) Answer: B
11) Answer: B 12) Answer: A 13) Answer: B 14) Answer: B 15) Answer: