A tram is moving with an acceleration of 49 cm `.s^(-2)` using 50% of its motor power the remaining 50% is used up to overcome friction. Find the coefficient of friction between the wheel and the tram line.

Explanation

Let the power of the motor be P and the mass of the tram be m. Let the distance covered by the tram in time t be s. As per given conditions work against friction per second
`(mu mgxxs)/(t) = Pxx 50% = (P)/(2) " "cdots(1)`
and rate of work done for the accelerated motion,
`(maxxs)/(t) = Pxx50%= (P)/(2)` [ where a = acceleration] `" "cdots(2)`
Now dividing (1) by (2) we get ,
`:. " " (mug)/(a)= 1 " ""or", mu = (a)/(g) = (49)/(980) = 0.05`.