ASSIGNMENT 5.2
( MODULE 5.3 )
MECHANICAL ENERGY
1. Define kinetic energy.
2. Calculate the kinetic energy of
(a) 1 kg mass of a toy car moving at 2 m/s.
(b) 2g of bullet traveling at 400 m/s.
(c) 500 kg car traveling at 72 km/h.
3. Compare the kinetic energy of a 20,000-kg truck moving at 110 km/h with that of an 80.0-kg
astronaut in orbit moving at 27,500 km/h.
4. How much work is require to accelerate a car of mass 2000 kg from 30 to 40 km/h.
5. An 8.0-g bullet with a speed of 800 m/s is shot into a wooden block of 40 kg which is at rest. The
bullet don’t passes through the block but it penetrates 20 cm into the block. How much does the block
move? (Hint : Consider the work done on the block.)
6. What is gravitational potential energy? Is this energy apply for any object even if they are not even on
Earth?
7. Ruppell’s vultures are known as the birds of highest flights that reach about 37,000 feet above sea
level. How much potential energy would they have for this kind of flight? How much work have they
done when they fly down to the level of 30,000 feet?