Q14 of 28 Page 69

Can any object have momentum even if its mechanical energy is zero? Explain.

No, any object cannot have momentum if its mechanical energy is zero. Mechanical energy is sum of both potential energy and kinetic energy.

Which means that there is no PE and KE.



= 0
 ⇒ v = 0


Now, momentum = mv = m(0) = 0


Hence, there will be no momentum.


More from this chapter

All 28 →
12

A boy is moving on a straight road against a frictional force of 5 N. After travelling a distance of 1.5 km he forgot the correct path at a round about (Fig. 11.1) of radius 100 m. However, he moves on the circular path for one and half cycle and then he moves forward upto 2.0 km. Calculate the work done by him.

 13

Can any object have mechanical energy even if its momentum is zero? Explain.

 15

The power of a motor pump is 2 kW. How much water per minute the pump can raise to a height of 10 m? (Given g = 10 m s–2)

 16

The weight of a person on a planet A is about half that on the earth. He can jump upto 0.4 m height on the surface of the earth. How high he can jump on the planet A?