University:
Kentucky State University
Course:
PHY 211 | General Physics I
Academic year:

2024
Views:

390

Pages:

3
Author:

FrextWhestembki

Dynamics second exam - Question (1):- The 1500-kg car has a velocity of 30 km/h up the 10-percent grade when the driver applies more power for 8 s to bring the car up to a speed of 60 km/h. Calculate the time average F of the total force tangent to the road exerted on the tires during the 8 s. Treat the car as a particle and neglect air resistance. Solu V 30 km/h 30*1000=8.333円/5 N = 60 km/n = At = 85 mv Fdt + (1500)(8.333)+ 9600 60% 1000-16.667 m/s 3600 =mv (15000/481) F-Wsin (5.711) dt = (1500) (16.664) F= 3026.93N weos(5. Question (2):- The assembly starts from rest and reaches an angular speed of 150 rev/min under the action of a 20-N force 7 applied to the string for / seconds. Determine 1. Neglect friction and all masses except those of the four 3-kg spheres, which may be treated as particles. Question (3&4):- The pinion A of the hoist motor drives gear B, which is attached to the hoisting drum. The load I. is lifted from its rest position and acquires an upward velocity of 2 m/s in a vertical rise of 0.8 m with constant acceleration. As the load passes this position, compute (a) the acceleration of point Con the cable in contact with the drum and (b) the angular velocity and angular acceleration of the pinion A. Question (5): The two V-belt pulleys form an integral unit and rotate about the fixed axis at O. At a certain instant, point A on the belt of the smaller pulley has a velocity v1.5 m/s, and point B on the belt of the larger pulley has an acceleration as = 45 m/s² as shown. For this instant determine the magnitude of th acceleration ac of point C. Question (6):- The 200-kg lunar lander is descending onto the moon's surface with a velocity of 6 m/s when its retro-engine is fired. If 4 s which varies with time as shown and then cuts off, calculate the velocity of the lander when landed. Gravitational acceleration at the moon's surface is 1.62 m/s². the engine produces a thrust 7 for 1-5s, assuming that it has not yet Question (7&8):- FB.D For an interval of its motion the piston rod of the hydraulic cylinder has a velocity v4 m/s which is increasing by 3 m/s each second as shown. At a certain instant B = 60. = (a)For this instant determine the angular velocity @BC of link BC (b) For this instant determine the angular acceleration of link BC.