1.

A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude P_0. The instantaneous velocity of this car is proportional to

Answer»

`t^2 P_0`
`t^(1//2)`
`t^(-1//2)`
`t/(sqrtm)`

SOLUTION :`P_0 = Fv :. F = ma = m(dv)/(dt)`
`:. P_0 = mv (dv)/(dt) " or " P_0dt = mvdv`
INTEGRATING both SIDES, we get
`int_(0)^(t) P_0 dt = m int_0^vvdv , P_0t = (mv^2)/(2) , v = ((2P_0t)/(m))^(1//2)` or `v PROP sqrt(t)`.


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