A tennis ball launcher works by using a spring to propel the ball forward as shown in the picture.
One model of tennis ball launcher has advertised that it is capable of imparting 15,000 of
kinetic energy to a 0.5 kg ball initially at rest. A student carefully measures the compression of
the spring to be 0.10 m.
um
What is the elastic energy stored in the spring?*
(6 Points)

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

The weights of bags filled by a machine are normally distributed with a standard deviation of 0.05 kilograms and a mean that can be set by the operator. at what level should the mean weight be set if it required that only 1% of the bags weigh less than 9.5 kilograms? round the answer to 2 decimal places.

Four identical lab carts each have a mass of 200 kg. different masses are added to the carts and the velocities are measured. all carts move to the right.