Hi! I'm not very sure how to solve the integral of speed. Please help. Thank you

1. Consider a mass m initially at rest at a large distance I from center of the earth (l>R the earth's radius). The mass m is released and falls toward the earth. (a) Calculate the speed of the mass as a function of its distance x from the center of the earth. (b) In the approximation that l> >R, how much time does it take for the mass m to reach the earth? Express your answers in terms of R, l, g (acceleration at the earth's surface) and (for part a) x