Help me please with physics

a) After 4.0 seconds, the mass will have a speed of 9.75 m/s. The equation used to solve for this is v = (F - μFn)/m, where F is the applied force, μ is the coefficient of friction, Fn is the normal force, and m is the mass. In this case, F = 65 N, μ = 0.15, Fn = mg = (25 kg)(9.81 m/s2) = 245.25 N, and m = 25 kg. Therefore, v = (65 N - 0.15*245.25 N)/25 kg = 9.75 m/s. b) The speed of the mass after being moved 2.0 m will depend on the total duration and the amount of friction present. If the force of friction remains constant, then the mass will continue to slow down until it reaches a terminal velocity, which is equal to the maximum speed it can achieve before the frictional force overcomes the applied force. To calculate the speed of the mass after 2.0 m, one must first calculate the total time taken by using the equation t = 2.0 m/(F/m - μFn/m) = 2.0m/(65N/25kg - 0.15*245.25N/25kg) = 0.1496 s. The speed of the mass at this time can