a ball is thrown straight into the air. The ball's gravitational potential energy at its peak height was 0.4J, and it's speed when it hit the ground was 4m/s. What was the mass of the ball?

What is the fate of the electrons that interact with a specimen in an electron microscope?

Which is the most accurate name for the ionic compound cas?

Consider two less-than-desirable options. in the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. in the second option you are driving 30 mph and crash head-on into a stationary brick wall. in neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. which of these two situations would result in the greatest impact force?