Assume 'A' does 500 J of work in 'x' minutes and 'B' does 1000 J of work in 20 minutes. If the power delivered by 'A' is P1 and 'B' is P2 and P1 = 2P2, then 'x', in minutes is :

Power is defined as the rate at which work is done, expressed by the formula P = W/t, where W is work and t is time. For person B, the work done (W2) is 1000 J and the time (t2) is 20 minutes. Thus, the power P2 = 1000/20 = 50 J/min. The problem states that the power delivered by A (P1) is twice that of B (P1 = 2P2). Therefore, P1 = 2 * 50 = 100 J/min. For person A, the work done (W1) is 500 J in 'x' minutes. Using the power formula for A, P1 = W1/x, we substitute the known values: 100 = 500/x. Solving for x gives x = 500/100 = 5 minutes. This calculation demonstrates the inverse relationship between power and time for a fixed amount of work.