1. In the following figure, suppose a person is trying to move a 51 kg block by pulling upward with a force F at an angle of 30o. above the horizontal. Assume the coefficient of kinetic friction μk=.4.
![153_A person is trying to move a block.png](https://secure.tutorsglobe.com/CMSImages/153_A%20person%20is%20trying%20to%20move%20a%20block.png)
a) How hard does the person have to pull to keep the block moving with constant velocity?
b) Is this easier or harder than pulling horizontally?