Which of the following statement is true about waves?
a. always have the same speed in a medium
b. a wave has the same speed in all media.
c. a wave has the same speed in a medium
d. sound waves are faster than light waves

Yvette hangs a 2.4kg bird feeder in the middle of a rope tied between two trees. the feeder creates a tension of 480 n in each side of the the rope.

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up

An engine undergoes a cycle as shown in the diagram. during a complete cycle the work done by the gas is 28.5×103 j and the energy transferred thermally out is 99.4×103 j. there are 1.5×1024 gas molecules and they have three active degrees of freedom. 6. (6 pts) during which process(es) is energy transferred thermally into the gas? a. 1→2 b. 2→3 c. 4→1 d. 1→2 and 4→1 e. none of the above