What force causes an elevator to go up?

Water at room temperature of 20.0°c is poured into an aluminum cylinder which has graduation markings etched on the inside. the reading in the graduations is 300.0 cc. the cylinder with the water in it is then immersed in a constant temperature bath at a temperature of 100°c. what is the reading for the level of water on the graduations of the cylinder after the water and the cylinder reach thermal equilibrium with the bath? the volume coefficient of expansion of water is 2.07 x 10^-4 k-1, and the linear coefficient of expansion of aluminum is 23.0 x 10^-6 k-1. a) 305.0 cc b) 304.0 cc c) 303.5 cc d) 303.3 cc e) 304.5 cc

An object is 10 cm from the mirror, its height is 1 cm and the focal length is 5 cm. what is the image height? (indicate the object orientation by including the + or - sign with the answer.) hi = cm +1 -1 +10 -10

How does changing the frequency affect the energy of the wave?