Question

A young boy is pulling his wooden toboggan up a 30° slope. If the toboggan is moving at a constant speed on the dry snow of the slope, calculate the minimum force the boy must exert in order to pull the toboggan, if the mass of the toboggan is 15 kg.

So, the forces acting on the toboggan are force of gravity and force of friction. The coefficient of kinetic friction is 0.18. I've drawn the diagram, and found Fg = 147 N. I've found the components, which are Fgx = 127.3 N, and Fgy = 73.5. My teacher told me how to finish this question and I can't remember how. Please help!

Answer 1

There is one force you did not mention in your 2nd paragraph. The force of the boy pulling the sled at 30degree's. Does that help?

Answer 2

I'm still kind of confused because my teacher mentioned adding the Fgy component to the Fg or something and then something to do with friction and Fgx but I can't remember what he said..

Answer 3

Sorry, I should also correct this, it says the *minimum force the boy must exert. I don't know if that makes a difference.

Answer 4

That also may have been for a different question; I'm really not sure. Does any of what I tried to say make sense?

Answer 5

the Minimum force the boy must exert is HUGE!! That means that if you take a snapshot at a particular time then Fnet=0.
Start with Newtons 2nd law \[\sum Fx \sum Fy\]

Answer 6

Rotating your coordinate plane may help you eliminate some variables, maybe try putting your X-axis at a 30degree angle?

Answer 7

This is the diagram I have that my teacher helped me draw:

Answer 8

this should help you guys.
you can add on it by clicking on "Reply with graph"

Answer 9

electrokid has the correct FBD, yours is still missing the minimum force F that the boy is exerting on the toboggan.
From his FBD, you have to resolve the force of gravity into x and y components then use newtons second law in x and y directions.

Answer 10

"F" is what we need to find.. how can you proceed without that! lol