Compute each part of given problem:

Problem: Two skaters are traveling toward each other. The left skater has a mass of 75 kg while the right skater has a mass of 90 kg.

Part A: If the left skater sees (in her frame) the right skater moving toward her with a speed of 2.3 m/s. To someone standing (at rest) on the pavement, the right skater is moving with a speed of 1.2 m/s to the left. Find the speed of the left skater relative to the person standing on the pavement.

Part B: Find the center-of-mass velocity of the two skaters in the pavement.

Part C: If the two collide elastically, and the right skater is moving at 1.98 m/s to the right after the collision, find the final velocity of the left skater.

Part D: Show that kinetic energy is conserved in the collision.

Part E: Show that the center-of-mass velocity is the same before and after the collision.

I've been having quite a bit of trouble understanding this problem, Thank you so much for your help. Thanks.