Asolar powered robotic rover on mars finds a spherical rock with a mass of 2.5 kg. the rover picks up the rock and lifts it 20.0 cm straight up. the rock has a specific gravity of 4.65. the gravitational acceleration on mars is 3.7 m/s^2. if the robot's lifting arm has an efficiency 40.0% and required 10.0 seconds to lift the rock 20 centimeters, how much electricity (in watts) did the arm use?

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.