Im stuck i need help

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

Asap i'm in class rn a 1,000-kg car is traveling 20 m/s on a flat stretch of road. it gets to a hill and coasts uphill until it stops. how high up the hill does the car travel? givens: equation: 1/2mv2initial=mghfinal solve for h. plug & chug, label.

In an experiment, how can i change human errors? be specific.