1) It takes 26.5 N to pull a 72 kg sled across snow. What is the coefficient of friction?
The 26.5N. is all friction.
Normal force from snow = (mg) = (72 x 9.8) = 705.6N.
µ = (26.5/705.6) = 0.0376
2) A 565 N rightward force pulls a large box across the floor with a constant velocity of 0.75 m/s. If the coefficient of friction is 0.8, what is the weight of the box?
The friction is 565N.
(565/ 0.8) = 706.25N. weight.
3) A rightward force of 246 N is applied to a 35 N suitcase to accelerate it across the floor. The coefficient of friction between the crate and the floor is 0.75. What is the acceleration of the crate?
(35/g) = mass of 3.57kg. (g=9.8 m/s^2).
(35 x 0.75) = 26.25N. friction.
(246 - 26.25) = net 219.76N. accelerating force.
Aceleration = (f/m) = (219.76/3.57) = 61.56m/s^2.
4) If a 1500 N force is exerted on a 200 kg statue to move it across the floor. If the coefficient of friction is 0.37, what is the crate's acceleration?
200 x g = normal force of 1,960N.
Friction = (1,960 x 0.37) = 725.2N.
Net accelerating force = (1500 - 725.2) = 774.8N.
Acceleration = (f/m) = (774.8/200) = 3.874m/sec^2
