How long does it take the sun to melt a block of ice at 0âc with a flat horizontal area 1.0 m2 and thickness 1.8 cm ? assume that the sun's rays make an angle of 37 â with the vertical and that the emissivity of ice is 0.050?

A10 kg box initially at rest is pulled 18 meters across a horizontal, frictionless surface by a 40 n force. what is the block’s final velocity over the 18 meters?

A51 kg woman skis down a hill and her kinetic energy is 9.96e4 j. what is her speed?

A75-hp (shaft output) motor that has an efficiency of 91.0 percent is worn out and is to be replaced by a high-efficiency motor that has an efficiency of 95.4 percent. the motor operates 4368 hours a year at a load factor of 0.75. taking the cost of electricity to be $0.12/kwh, determine the amount of energy and money saved as a result of installing the high-efficiency motor instead of the standard motor. also, determine the simple payback period if the pu