1. If the acceleration due to gravity in a certain place is 10 m/s2, then calculate the potential energy of a body, which mass is :
a. 4 kg at the height of 25 m above the ground
b. 1.5 x 10-5 gram at the height of 6 x 106 cm
2. Calculate the kinetic energy owned by :
a. car of 2500 kg which moves velocity of 72 km/hour
b. a ball 80 gram which moves with velocity of 15 m/s
3. A stalled car is pushed by 3 people. They are Iman with pulling force of 300 N, Ferry of 500 N, and Dias with pulling force of 600 N. The car moves as far as 200 m from the initial place.
a. What is work of each people ?
b. What is total force that moves the car ?
c. What is total work of the three people ?
