Hi! I need help with parts d,f, and g.

(13%) Problem 3: A meteoroid is moving towards a planet. It has mass m = 0.82 x 10' kg and speed v1 = 2.9 x 10' m/s at distance R1 = 1.9 x 10' m from the center of the planet. The radius of the planet is R = 0.46 x 10' m. The mass of the planet is M = 3.6 x 1025 kg. There is no air around the planet. mov, R1 R @theexpertta.com 14% Part (a) Enter an expression for the gravitational potential energy PE, of the meteoroid at Ri in terms of defined quantities and the gravitational constant G. Assume the potential energy is zero at infinity. PEI = - GM m/R1 Correct! 14% Part (b) Calculate the value of PE1, in joules. PEI = - 1.03 ( 1017) PEI = -1.030 x 1017 J Correct! 14% Part (c) Enter an expression for the total energy E1 of the meteoroid at R1 in terms of defined quantities. E1 = 1/2 m v12 - GM m/R1 Correct! * 14% Part (d) Calculate the value of E1, in joules. E1 = -9.11 ( 1016) E1 =-9.110 x 1016 J * Attempts Remain 14% Part (e) Enter an expression for the total energy E of the meteoroid at R, the surface of the planet, in terms of defined quantities and v, the meteoroid's speed when it reaches the planet's surface. E =-GM m/R + 1/2 m v2 . Correct! * 14% Part (f) Enter an expression for v, the meteoroid's speed at the planet's surface, in terms of G, M, v1 , R1 , and R. v = V( 2 GM ) ( 1/R - 1/R1 ) + v12 * Attempts Remain A 14% Part (g) Calculate the value of v in meters per second. Grade Summary v = m/s Deductions 0% Potential 100%