A 72 kg sled Is pulled forward from rest by a snowmobile and accelerates at 2 m/s squared forward for five seconds. The force of
friction acting on the sled is 120 N backwards. The total mass of the snowmobile and driver is 450 kg. The drag force acting on the snowmobile is 540 N backwards. What is the tension in the rope.
So first make a force diagram. I would label forward forces + and backward forces -. Essentially, the drag force is equal to the Ft (force of tension) + Ff (force of friction on snowmobile - driver system). The force of Friction is equal to mu * Fn. We can find mu through the force of friction acting on the sled. 120 N = mu * Fn (equal to m * g of sled). mu of the Ice is equal to 0.167. So, 540 N = Ft + 0.167 * 4500 N. Ft = -211.5 N. <u>Ft is acting in the backwards direction at a magnitude of 211.5 N</u>
The impulse is given by the magnitude of the force times the time interval: We can see that the force F of the 4 skateboard is always the same (33 N), this means that the skateboard with greatest impulse is the one with the largest time interval, so skateboard C).
