Suppose that you are swimming in a river while a friend watches from the shore. in calm water, you swim at a speed of 1.25 m/s . the river has a current that runs at a speed of 1.00 m/s. note that speed is the magnitude of the velocity vector. the velocity vector tells you both how fast something is moving and in which direction it is moving. if you are swimming upstream (i. a., against the current), at what speed does your friend on the shore see you moving?

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)

Chemical energy is a form of energy. a. heat b. kinetic c. potential d. electromagnetic

Coal contains energy. a. light b. kinetic c. chemical d. mechanical