A truck driver loads some oil drums into a truck by lifting them directly. Each drum has a mass of 80 kg and the platform of the truck is at a height of 0.8 m above thground. (a) What force is needed to lift a drum into the truck ? (b) How much energy is used up in lifting a drum? (c) After the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck. (d) The driver stops the truck at the factory gate. What happens to the kinetic energy of the truck ? Take g=10 m s^(-2)

A truck driver loads some oil drums into a truck by lifting them direc

1.	A truck driver loads some oil drums into a truck by lifting them directly. Each drum has a mass of 80 kg and the platform of the truck is at a height of 0.8 m above thground. (a) What force is needed to lift a drum into the truck ? (b) How much energy is used up in lifting a drum? (c) After the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck. (d) The driver stops the truck at the factory gate. What happens to the kinetic energy of the truck ? Take g=10 m s^(-2)
Answer» Solution :Given ,m=80 kg,h=0.8 m ,g=10 m`s^(-2)` (a)Force needed to lift a drum Force of gravity on drum (b)ENERGY used up in lifting a drum Gravitational potential energy mgh M `80xx10xx0.8=640J` (c )In MOVING the TRUCK ,the chemical energy of the fuel (diesel) changs into mechanical (kinetic) energy . (d)On stopping the truck ,the kinetic energy og the truck changes into the heat and sound ENERGIES.