A 742 kg wrecking ball is attached to a crane 7 m above the ground. What is the gravitational potential energy of the wrecking ball at this height?
A.
1,038.8 J
B.
50,901.2 J
C.
5,262.6 J
D.
7,330.4 J

Spend time observing or thinking about events that involve matter and energy. which events can you explain? which events can’t you explain?

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90

Lightning is an example of what phenomenon? a release of a large amount of energy an absorption of a large amount of energy a natural electric circuit a natural electric current