Two motor-bikes, A and B

PHYSICS · Multi-part · CBSE · Physics · Work and Energy · Work and Energy

Problem

Two motor-bikes, A and B, have masses

100\,\text{kg}

and

120\,\text{kg}

respectively. Bike A is travelling at

36\,\text{km/h}

while bike B is travelling at

30\,\text{km/h}

. (i) Calculate the kinetic energy of each bike in joule. (ii) Find the ratio

\mathrm{K_A} : \mathrm{K_B}

of their kinetic energies. (iii) How much additional kinetic energy must bike B gain so that its kinetic energy equals that of bike A?