Show that for a constant force F, P = F · v, where v is the instantaneous velocity vector. (b) A constant force of 40 N is applied to a body as the body moves uniformly at a speed of 3.5 m/s. The force does work on the body at a rate of 90 W. What is the angle between the force and the direction of motion of the body?

Marisa pushes a 1.635 kg book across a table, accelerating it at a rate of 2.099 m/s^2 over a time period of 1.891 s. If 2.760 watts of power were used to move the book, what distance does the book travel across the table?

A rocket is descending to the surface of Mars where g = 4 m/s ^ 2 . The rocket is initially 80 m above the planet's surface and is descending downward at 50 m/s. The mass of the rocket is 2500 kg. The rocket will land on the surface with a final velocity of 0. Our goal is to find the upward thrust force on the rocket to make this happen.   Find the thrust force on the rocket ?   Answer is 49,000 N, please show work.

A luge and its rider, with a total mass of 79.0 kg, emerge from a downhill track onto a horizontal straight track with an initial speed of 31.0 m/s. If a force slows them to a stop at a constant rate of 1.50 m/s², (a) what magnitude F is required for the force, (b) what distance d do they travel while slowing, and (c) what work W is done on them by the force? What are (d) F, (e) d, and (f) W if they, instead, slow at 3.00 m/s²? (a) Number (b) Number 320.33 (c) Number (d) Number (e) Number 118.5 (f) Number i Units Units 101 Units Units Units Units N m 1000

You are using a modified block and tackle pulley system to lift a concrete block. You need to lift the concrete block (mass = 200 kg) a distance of 5 meters upward. The system is designed to reduce the force load of 4. How much rope must you pull down on the other side of the pulley to lift the block the proper distance? Hint: There is a very simple way to solve this if you remember that work in = work out.