How Does Force Direction Affect Work Done?

[Tdollarhyde]

A force of F = 35 N is used to drag a crate 7 m across a floor. The force is directed at an angle upward from the crate so that the vertical component of the force is Fv = 21 N and the horizontal component is Fh = 28 N as shown in the diagram.

(a) What is the work done by the horizontal component of the force?
196 Joules
(b) What is the work done by the vertical component of the force?
? Joules
(c) What is the total work done by the 35 N force?
? Joules

Can't figure out how to do the last 2 for the life of my. You don't even have to do it for me, I'll be good with just an equation.

Also, Here is another one I can't figure out:

An ice skater with a mass of 89 kg pushes off against a second skater with a mass of 30 kg. Both skaters are initially at rest.
(a) What is the total momentum of the system after they push off?
? kg·m/s
(b) If the larger skater moves off with a speed of 1.8 m/s, what is the corresponding speed of the smaller skater?
? m/s

 

[Tdollarhyde]

Wow, I'm stupid. The vert. force is doing 0 work, and the overall work is the same as the horizontal work!

 

[PhanthomJay]

Not stupid, just an oversight. Try the 2nd question and show an attempt if you still need help with that one.

 

[Tdollarhyde]

Not stupid, just an oversight. Try the 2nd question and show an attempt if you still need help with that one.

Well, the total momentum is 0, and the second skater was going somewhere around 5 something. Have since put it away.