Alejandro measured the speed of sound in different materials. He recorded his data in the table, as shown. Materials Speed (m/s)
rubber 60
air 343
lead 1,210

What can he conclude about the speed of sound in these materials?
A.
Sound travels faster in lead than in air or rubber.

B.
Sound travels slower in lead than in air or rubber.

C.
Sound travels faster in air than in lead or rubber.

D.
Sound travels slower in air than in lead or rubber.

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?