When the child is moving, he/she has kinetic energy. For just a brief second before they move the other way, the child is not moving, but they have gravitational potential energy.
The child may need a push from time to time because friction with the air causes loss of energy.
Conductivity is the property of matter in which a substance can transfer heat or electricity
Answer:
F = M a
W = M g equivalent equation to express weight of object of mass M
M = W / g = 2867 N / 9.8 m/s^2 = 292.6 kg
Answer:39.88 rad/s
Explanation:
Given
mass of cylinder m_1=18 kg
radius R=1.7 m
angular speed 
mass of
dropped at r=0.3 m from center
let
be the final angular velocity of cylinder
Conserving Angular momentum





Your being on the moon has no effect on the moon's
gravitational field strength, or on the Earth's for that
matter.
However, YOU notice a change on YOU when YOU move
from one to the other, because of the effect of the gravitational
field strength on you and your internal organs.
If you could stand on the moon, you would experience an incredible
sense of lightness, since the forces of attraction between the moon
and anything else are only 16% as great as the same forces are on
Earth.