Question

During the latter part of the motion of a rocket its mass is halved because the fuel is used up, while its velocity increases by a factor of 10. By what factor does the kinetic energy of the rocket increase during this stage? A. 5 B. 10 C. 50 D. 100

Answer 1

We know that,

K.E={[1/2]*m*V^2}

given that,

mass is halved

so, m=m/2

and velocity increases by a factor 10

that is,V=10V

then,

KE ={[1/2]*[m/2]*[10V]^2}

KE ={[1/2]*[m/2]*[100V^2]}

KE =50{[1/2]*m*V^2}

so, option C is correct answer.