Molecules at room temperature move freely. What happens to the molecules when heat is removed until it freezes?

Molecules group together
Molecules slow down and contract
Molecules speed up and expand
Molecules move freely

The crank oa rotates in the vertical plane with a constant clockwise angular velocity ω0 of 5.6 rad/s. for the position where oa is horizontal, calculate the force under the light roller b of the 10.6-kg slender bar ab.

Alead ball is dropped into a lake from a diving board 5m above the water . it hits the water with a certain velocity and then sink with constant velocity in bottom . it reaches the bottom 5 second after it is dropped if g= 10m/s2 . find depth of the lake and average velocity of the ball ?

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?