Abicycle and its rider have a combined mass of 80 kg and a speed of 6 m/s. what is the magnitude of the average force needed to bring the bicycle and its rider to a stop in 4 seconds?

Rank the torques on the five doors shown in the figure above from least to greatest. note that the magnitude of all the forces is the same

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space. b. we'll know it immediately because it will be brighter than the full moon in the sky. c. we won't know about it until 600 years from now. d. none of the above.

An isotope undergoes radioactive decay by emitting radiation that has a –1 charge. what other characteristic does the radiation have?