Question 2: a) John is pushing a sled in the gym. The sled mass is 30 kg and the weight of the plates on top of it are 490.5 N. The coefficient of static friction between the floor and sled is ?s = 0.25. If John is applying a force in the horizontal direction (see figure below), how much force does he need to apply to start the movement of the sled? b) If John pushes the sled on Mars (the same way he does in part a), where gMars = 3.73 m/s², how much force does he need to apply to start the movement of the sled? c) If John is applying a horizontal force equal to 400 N to the sled on earth, and the coefficient of dynamic friction is ?d = 0.1, what is the magnitude of the friction force resisting the movement of the sled? d) In c, what will be the magnitude and angle of the resultant force applied to the sled? * Drawing free-body diagram for question 2 and 3 is essential and worths points. Horizontal
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The weight of the sled is its mass times the acceleration due to gravity (g = 9.8 m/s^2), so it's 30 kg * 9.8 m/s^2 = 294 N. The total weight is then 294 N + 490.5 N = 784.5 N. The force of static friction is the coefficient of static friction times the normal Show more…
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