For what height a black of ice be dropped in order that it may completely melt. it is assumed that 20% of energy's of fall is retained by ice.[L=80 cal/gm]

How does the kinetic energy of a charge change as the charge moves under the effect of an electric field from higher potential to lower potential? a. the kinetic energy increases. b.the kinetic energy decreases. c.the kinetic energy remains the same. d.the kinetic energy is always zero.

Which lists the fundamental forces in order, from strongest to weakest? strong nuclear, weak nuclear, electromagnetic, gravitational strong nuclear, electromagnetic, weak nuclear, gravitational gravitational, weak nuclear, electromagnetic, strong nuclear electromagnetic, gravitational, strong nuclear, weak nuclear

What was the first instrument to ever record an earthquake?