chapter 9

Question 1

Law of universal gravitation

Answer 1

Every body in the universe attracts every other body with a force that, for two bodies, is directly proportional to the product of their masses and inversely proportional to the square of the distance between thier centers:

F= G m^1m^2/ d^2

Question 2

Inverse-square law

Answer 2

A law that relates the intensity of an effect to the inverse square of the distance from the cause. Gravity follows an inverse square law., as do the effects of electric, magnetic, light, sound, and radiation phenomena

Question 3

Weight

Answer 3

the force that an object exerts on a supporting surface which is often, but not always, due to the force of gravity.

Question 4

Weightless

Answer 4

Being without a support force, as in free fall. `

Question 5

Spring tides

Answer 5

high and low tides that occur when the Sun, Earth, and Moon are all lined up so that the tides due to sun and moon coincide, making the high tides higher than average and the low tides lower than average.

Question 6

Neap Tides

Answer 6

tides that occur when the moon is midway between new and full, in either direction. tides due to the sun and the moon partly cancel, making the high tides lower than average and the low tides higher than average.

Question 7

Gravitational field

Answer 7

the influence that a massive body extends into the space around itself. producing a force on another massive body. it is measured in newtons per kilogram.

Question 8

Black Hole

Answer 8

a concentration of mass that results from gravitational collapse, near which gravity is so intense that not even light can escape.