The Doppler Effect for sound occurs when: a) the speed of the wave changes
b) the height of the wave changes
c) the distance between the waves change
d)the moving object decreases in speed

Two friends are having a conversation. anna says a satellite in orbit is in freefall because the satellite keeps falling toward earth. tom says a satellite in orbit is not in freefall because the acceleration due to gravity is not 9.80 m/2 . who do you agree with and why?

True or false: the cycle of seasons on the earth is caused by the tilt of the earth on its axis toward and away from the sun.

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star