Q10 of 28 Page 69

A rocket is moving up with a velocity v. If the velocity of this rocket is suddenly doubled, what will be the ratio of two kinetic energies?

Initial velocity = v =v’= 2v

Initial kinetic energy =


Final kinetic energy (K.E.)



(K.E) initial : (K.E) final = 1:4


More from this chapter

All 28 →
8

Water stored in a dam possesses

 9

A body is falling from a height h. After it has fallen a height h/2, it will possess.

 11

Sunita can run with a speed of 8 m s–1 against the frictional force of 10 N, and Kapil can move with a speed of 3 m s–1 against the frictional force of 25 N. Who is more powerful and why?

 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.