A father gives his son a ride by pulling a sled across the rough snow. The father runs across the snow with a constant acceleration while pulling the sled at F = 75.0 N, at 30 deg. above the horizontal. The combined mass the sled and son is 30.0 kg. The coefficient of kinetic friction between the sled and the snow is Uk = 0.200.
a) What is the magnitude of the normal force exerted on the sled-son system?
sum of Fx: -fk + 75cos30 = max
sum of Fy: n-mg +75sin30 = may
This is as far as I got and I'm not even sure if it's correct. Please provide a concise solution so that I can see exactly what's going on. I need to master Newton's laws. I have pressure of college approaching. If I see the way, I can solve problems. Also, I don't just want solution as not knowing what is happening won't help me on a test. I have tried to solve it on paper. It is tedious to put my inaccurate solution on here. Thank you so much.
b) What is the magnitude of the acceleration of the sled-son system?
I may have figured it out: Here's the solution.
sum Fx: 75cos30 - 0.200 = max
sum Fy: n-mg + 75 sin30 = 0
n = mg - 75 sin30
n = (30*9.8) - 75sin30
n = 257 N
b) a = (75 cos 30 - 0.200) / 30kg
a = 2.2 m/s^2
check my thinking.
0 answers