a car on a roller coaster is in its lowest position on its circular track and the apparent weight of one of the riders is 4.0 times her actual weight. if the radius of the circular track is 19m find the speed of the roller coaster.

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

4. who was the first one to measure the speed of light and conclude that it is finite? 5. who was the first philosopher who thought the speed of light is finite? 13. what is the speed of light numerically? 14. give an example of something moving faster than light 15. give an example for some particles or waves that

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply