Question

A The length of the roller coaster track is 100 ft and the elevation change of the track from point A, at the bottom of the track, to point B, at the top of the track is 20 ft. The roller coaster car, including the passengers, weights 1,200 lb, and the force of friction between the car and the tracks is 20 lb. The speed at point A is 45 ft/s. Determine the speed at point B.

B Solve the above problem, neglecting friction.

C A 500 lb box slides at 20 ft/s along a horizontal surface (?k = 0.3). A 300 lb force is then applied at an angle of 30 degrees relative to the surface, for 2 seconds. Determine the final speed of the box.

Answer 1

Solutiu here elevahion (h): 2o t. (biw Paint A kB) weight herR, レ %二11.53. ve bicl As, the veliicl neoves wd nw

1e1o, are (12 to Sin川59-t 2.0)%2.174 32.14s 12 Cv 91), where herR, CL) a 6.967 bt/s 2 2025-1393.4 chent)

V205- 12%6.44 F BD 3o 20 bt/s here, hime (t) 2 sec, 650 b to move n orrard olirechon

0.3x650 mas m) 64.3 x32.174 万DO here initial velotity (u)s 20 t/s time (t) 2 sec v = 28.34 kt/s lan