A 560-kg projectile is fired at an angle of 300deg above

Question

Solve the all parts of following question:

Question: A 56.0-kg projectile is fired at an angle of 30.0° above the horizontal with an initial speed of 1.28 x 10² m/s from the top of a cliff 138 m above level ground, where the ground is taken to be y = 0.

Part A: What is the initial total mechanical energy of the projectile?

J

Part B: Suppose the projectile is traveling 90.7 m/s at its maximum height of y = 309 m. How much work has been done on the projectile by air friction?

J

Part C: What is the speed of the projectile immediately before it hits the ground if air friction does one and a half times as much work on the projectile when it is going down as it did when it was going up?

m/s

I am not able to get the correct answer please help me. Thanks.