A5000-kg freight car crashes into a 10,000-kg freight car at rest. they couple upon collision and move with a speed of 2 m/s. what was the initial speed of the 5000-kg freight car? a 5000-kg freight car crashes into a 10,000-kg freight car at rest. they couple upon collision and move with a speed of 2 m/s. what was the initial speed of the 5000-kg freight car? a) 4 m/s b) 8 m/s c) 6 m/s d) 5 m/s e) none of the above

Aprojectile is launched horizontally 10m above the ground and with an initial velocity of 15 m/s. a) determine the magnitude and direction of projectile velocity at t= 1.3s b) determine the magnitude and direction of projectile acceleration at t=1.3s

This question is worth 54 points ! rock falls from a ledge to the ground what energy conversion occurs during this process a potential to kinetic b kinetic to potential c thermal to mechanical d chemical to mechanical

Imagine you are riding on a yacht in the ocean and traveling at 20 mph. you then hit a golf ball at 100 mph from the deck of the yacht. you see the ball move away from you at 100mph, while a person standing on a near by beach would observe your golf ball traveling at 120 mph (20 mph + 100 mph). now imagine you are aboard the hermes spacecraft traveling at 0.1c (1/10 the speed of light) past mars and shine a laser from the front of the ship. you would see the light traveling at c (the speed of light) away from your ship. according to einstein’s special relativity, how fast will a person on mars observe the light to be traveling? a) 0.1c (1/10 the speed of light) b) c (the speed of light) c)1.1c (c+0.1c)