Why do objects at the bottom of an aquarium filled with water appear closer then they actually are?

What color would an object that reflects green and blue light appear to be in white light? a. blue b. cyan c. magenta d. black

Name three different units of energy used to measure heat and describe what type of situations each is usually used.

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.