A world-class tennis player can serve a tennis ball at 130 mi/h mi/h (about 58 m/s m/s ). The length of a tennis court is 78 ft ft . Approximately how long does an opponent have to react from the instant the ball is served until the ball reaches the opponent?.

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)

Which situation will have the highest resistance? a. long wire and high temperatureb. short wire and high temperaturec. long wire and cold temperaturedshort wire and low temperature

Critical mass is the of material required to produce a chain reaction. a.) minimum amount b.) atomic mass c.) precise amount d.) maximum amount