[" 39A particle is moving "long "x" -axis has acceleration "],[f" ,at time t,given by,f "f_(0)(1-(t)/(T))," where "f_(0)" and "],[" T are constants.The particle at "t=0" has zero "],[" velocity.In the time interval between "t=0" and "],[" the instant when "f=0," the particle velocity "(v_(x))],[" is- "]