A distant star, Proxima Centauri is 40.2 trillion km away. Convert this distance to light years (if 1 light year is 9.7 trillion Km). Show your calculation.

Avery hard rubber ball (m = 0.5 kg) is falling vertically at 4 m/s just before it bounces on the floor. the ball rebounds back at essentially the same speed. if the collision with the floor lasts 0.05 s, what is the average force exerted by the floor on the ball?

Which is an example of gaining a static charge by conduction? a) rubbing a balloon against your hair. b) shuffling your shoes across a carpet. c) bringing a charged rod near an electroscope. d) touching your car on a cold day and getting a shock.

What is the relationship between the direction of motion of the balloon and the wind currents