Which sound has 1000 times more energy than the sound of a dishwasher?
a. chain saw (100 dB)
b. jackhammer (130 dB)
c. a lawnmower (90 dB)
d. tornado siren (140 dB)

Ais not a compound machine. a. bolt b. shovel c. handcart (dolly) d. see-saw (teeter totter)

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.

Which of the following changes will result in a stronger electromagnet? a. using fewer coils of wire b. using a higher voltage c. using a shorter nail d. using a longer wire