Mass of B is four times that of A, B moves with a velocity half that of A. Then B has :

The kinetic energy (KE) of an object is defined by the formula KE = 1/2 mv², where 'm' is mass and 'v' is velocity [t1][t3]. To compare the kinetic energies of objects A and B, let the mass of A be 'm' and its velocity be 'v'. Consequently, the kinetic energy of A (KE_A) is 1/2 mv². According to the problem, the mass of B is 4m and its velocity is v/2 [t8]. Substituting these values into the formula for object B: KE_B = 1/2 * (4m) * (v/2)² [t4]. Simplifying this expression, we get KE_B = 1/2 * 4m * (v²/4). The factors of 4 cancel out, resulting in KE_B = 1/2 mv². Therefore, the kinetic energy of B is exactly equal to the kinetic energy of A [t8]. This demonstrates that while velocity has a squared impact on energy, the fourfold increase in mass perfectly compensates for the halving of the velocity [t4][t7].