Acar of mass 1400 kg travelling at 15 m/s goes over a circular arc-shaped bump in the road. if the radius of the arc is 40 m, what is the normal force on the car as it is passing the top of the arc?

Idon’t quite understand this problem

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.

You throw a baseball directly upward at time =0 at an initial speed of 14.9 m/s. what is the maximum height the ball reaches above where it leaves your hand? ignore air resistance and take =9.80 m/s2.