In volleyball, how is the server determined?

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?

Four 5-gram blocks of metal are sitting out in the sun and absorb the same amount of heat energy. use the following specific heat capacity data to determine which block will increase its temperature the most.

Which of the following is not an appropriate unit for acceleration? (kg/12 mihr? m/min/sec cm/30c?