Look at photo C. The temperature of the air
in the room is -5 °C. The
temperature of the drinks is
70°C.
Will energy flow from the
drinks to the room or from
the room to the drinks?
Explain your answer.

Amachine, modeled as a simple spring-mass system, oscillates in simple harmonic motion. its acceleration is measured to have an amplitude of 5,000 mm/s with a fre- quency of 10 hz. compute the maximum displacement the machine undergoes during this oscillation.

What is the length x of the side of the triangle below? (hint: use the cosine function)

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?