Mr. L quits teaching and joins the circus to be shot out of cannons, his favorite pastime. On his first cannon launch he goes 100 meters in 4 seconds before he hits a tree that is directly south of the cannon. This means that Mr. L's average speed is and that his average velocity is. and that his average velocity is

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.

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.

What happens to an isotope during radioactive decay?