Recent content by BrettD

Couldn't you imagine the force as adding kinetic energy to the block as gravity changes that energy to potential energy at the same rate? Would taht be a valid interpretation?

Doesn't gravity just transform potential energy into kinetic energy, or vice versa?

Would it be correct to think of there being two types of forces, A) ones that add energy to a system and B) ones that do not add energy to a system? In the block example, the outside force is type A and gravity is type B. Statement 1) could be changed to: 1)Change in the block's potential...

The issue is that I think these things: 1)Change in the block's potential energy is the total work done on the block (Assuming no changes in other forms of energy) 2)Total work done on the block is 0 3)Change in potential energy is mgh Clearly, if 2 and 3 are true, the first can not.

Wouldn't the total work done on the block be the same as the sum of the work done by each force? Edit: ...and the total work done should be mgh, right?

Regarding the question "What is the total work done on Throcky by all forces?" I originally thought it would be the change in mgh, but my Physics teacher said that because he's in equilibrium between the force F and gravity, net force on him is 0, and so is work.

In a physics problem like similar to the block, where the acceleration was always near zero, my physics teacher said that no work was done because there was no acceleration, and the work from gravity canceled out the work done by the upwards force.

What would the work done on the block be over x meters? Isn't the net force equal to mass times acceleration, which in this case is 0?

Imagine a 100N block rising at a constant velocity with a 100N force in the vertical direction pulling it, and 100N of gravity pulling it down. The net force on the block is 0, so work, force time displacement, is also 0. However, the block is rising and clearly gaining gravitational potential...