Question
Please show the work with formulas and then I will full credit/rating.
A 100 lb block moves with an initial speed of 10 ft/s down the 30 degree incline while a constant (magnitude and direction) force P = 30 lb is applied to the rope as shown. When the block moves 2 ft down the incline, the work done on it by gravity is 6. 22 lb ft 100 lb ft 173 lb ft 200 lb ft 3220 lb ft. When the 100 lb block moves 2 ft down the incline, the work done on it by the force in the rope P = 30 lb is -52. 0 lb ft -60. 0 lb ft -90. 0 lb ft -112 lb ft When the 100 lb block moves 2 ft down the incline, the work done on it by the force of friction is - 17. 5 lb ft 25. 0 lb ft - 28. 3 lb ft - 35. 8 lb ft - 43. 3 lb ft. Two feet down the incline from its initial position, the speed of the block will be 8. 32 ft/s 9. 89 ft/s 10. 1 ft/s 10. 6 ft/s 12. 0 ft/s
Explanation / Answer
take help from this
http://www.physicsclassroom.com/class/vectors/u3l3e.cfm
http://www.youtube.com/watch?v=khsnIwot7Xk&noredirect=1
extra wrd to be done is to apply one tension in upward direction and two components of force P , one along the edge and one perpendicular to it. the balance the forces in two directions and get your answer