Question

The most widely accepted theory of the Moon’s origin is the Giant Impact theory. It purports that near the end of the Earth’s formation process, a Mars-sized projectile (named Theia) struck the Earth. This collision was so violent that material was tossed into orbit around the Earth from which the Moon formed. Let’s assume that the Earth had 90% of its current mass and the projectile had 10% of Earth’s mass. The projectile struck the Earth at 10 km/sec faster than the Earth was moving and that the Earth had an initial speed of 29.6 km/sec. Also assume that the entire projectile became part of the Earth (in other words, none of the projectile material escaped from the Earth-Moon system). a. Use this information to calculate the final speed of the Earth-Moon system after the collision. b. Calculate the percentage of the system’s original kinetic energy was lost in the collision. Where might this energy have gone?

Answer 1