Zaiden and Lisa are testing music’s effect on plants. What should their materials list include to guarantee they have a valid experiment that includes repetition?

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

What do you think car designers do if the damage caused by a crash test is too severe?

Which sound characteristic is not affected by the relative motion of an object