John and Haven move a large bookcase from the bedroom to the living room. The bookcase has a mass of 45 kg. They apply a force of 300 N to move the bookcase 8 m. It takes them 20 seconds to move the bookcase. How much work do they do to move the bookcase?

Tall pacific coast redwood trees can reach heights of about 100 m. if air drag is negligibly small, how fast is a sequola cone moving when it reaches the ground f it dropped from the top of a 100 m tree?

While you are driving in the lane next to the curb on a multi-lane road the car on your left suddenly moves toward you lane. they are about toy crash into your front fender. you

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?