You spot a friend on a bus while on your way to school. why does your friend appear to be at rest even though the bus is moving? a. you are waiting at the bus stop. b. you are in a car traveling at the same speed in the opposite direction. c. you are riding in the same bus.

A2 kg ball travellng to the right with a speed of 4 m/s collidees with a 5 kg ball traveling to the left with a speed of 3 m/s. take right to be the positive direction. what is the total momentum of the two balls before they collide? what is the total momentum of the two balls after they collide?

The speed of light in a material is 0.50 c. what is the critical angle of a light ray at the interface between the material and a vacuum?

If a balloon is taken outside on a very cold day, what will occur?