3. F rF is variable

6. The two quantities are equal ( Work, K.E theorem )

8. =2N =4N =3m/s Find the net power If F2=6N What will happen to Velocity in both cases A: Stay constant b: increase

9. I am John, sally is applying a force F and doing a work mgh but mg is doing a work -mgh so net work is zero and K.E should not change I am Sally, For me the book is stationary so F is doing no work as well as mg and K.E is zero and do not change. Laws of physics are the same in all inertial frames.