Suppose a moving car has 2000 j of kinetic energy. if the carʹs speed doubles, how much kinetic energy would it then have?
a) 8000 j
b) 6000 j
c) 1000 j
d) 4000 j
e) 2000 j

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Aperson touches a large chunk of ice with their hand and remarks, “this is making me cold.” explain what this person is feeling. is the ice transferring “cold” to the person? is there a heat transfer occurring? explain.

The drag force, fd, imposed by the surrounding air on a vehicle moving with velocity v is given by fd = cdaρv 2/2 where cd is a constant called the drag coefficient, a is the projected frontal area of the vehicle, and ρ is the air density. an automobile is moving at v = 80 kilometers per hour with cd = 0.28, a = 2.3 m2, and ρ = 1.2 kg/m3.