3. A 15.0 kg block is pushed up a 35° incline. The coefficient of friction between the block and the incline is 0.480. What minimum force would be needed to move the block up the incline
at a constant speed? (4 marks)
4. A child pulls an 8.50 kg toboggan across the sidewalk by exerting a 60.0 N force in the
direction shown. The coefficient of friction between the toboggan and sidewalk is
0.520. What is the acceleration of the toboggan? (5 marks)

3) F = 142 N

4) a = 2.84 m/s²

Explanation:

F = mgsinθ + μmgcosθ = mg(sinθ + μmgcosθ)

F = 15.0(9.81)(sin35.0 + 0.480cos35.0)

F = 142.260...

Did not show us the shown direction, so I will ASSUME that it is θ° above the horizontal. If it's below the horizon, just enter a negative value for θ.

EDIT:  OK  24° above the horizon

F = ma

60.0cosθ - 0.520(8.50(9.81) - 60sinθ) = 8.50a

a = 60.0cos24 - 0.520(8.50(9.81) - 60.0sin24) / 8.50

a = 2.84 m/s²

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.