A skier starts from rest on the 31° slope at timet = 0 and is clocked at t = 2.81 s as he passes a speed checkpoint 18 m down the slope. Determine the coefficient of kinetic friction between the snow and the skis. Neglect wind resistance.

The 210-kg crate rests on the ground for which the coefficients of static and kinetic friction are us = 0.5 and ui = 0.4, respectively. The winch delivers a horizontal towing force T to its cable at A which varies as shown in the graph. Originally the tension in the Part A cable is zero. (Figure 1) Determine the speed of the crate when t = 3.8 s. Hint: First determine the force needed to begin moving the crate. Express your answer to three significant figures and include the appropriate units. > View Available Hint(s) HA v = Value Units Submit Figure Provide Feedback T (N) 800 T= 400 1/2 t (s)

Block A has a mass of 55 kg, and block B has a mass of 11 kg. The coefficients of friction between all surfaces of contac are µs= 0.20 and Hk= 0.15. 25° If P= 0, determine the acceleration of block B. (You must provide an answer before moving on to the next part.) The acceleration of block B is m/s $ 25°.

Q23. As shown in the image below, the force acting on the 5-kg crate is a function of time. The coefficient of kinetic friction between the crate and the surface is uk= 0.14. Determine the crate's speed at t= 2.1 s if its initial speed v1 = 2.9 m/s. Please pay attention: the numbers may change since they are randomized. Your answer must include 2 places after the decimal point, and proper Sl unit. Take g = 9.81 m/s2. F = (201² +30)N (t in second) F. 30 V1 Your Answer: Answer units