The power of a bus engine is transmitted using the beltandpu
The power of a bus engine is transmitted using the belt-and-pulley arrangement shown. The engine turns pulley A at ?A=(20t+35)rad/s clockwise, where t is in seconds. (Figure 1)
Part A
Determine the angular velocity of the generator pulley B, measured clockwise, when t = 3 s.
Express your answer using three significant figures. Enter positive value if the angular velocity is clockwise and negative value if the angular velocity is counterclockwise.
| The power of a bus engine is transmitted using the belt-and-pulley arrangement shown. The engine turns pulley A at ?A=(20t+35)rad/s clockwise, where t is in seconds. (Figure 1) | Part A Determine the angular velocity of the generator pulley B, measured clockwise, when t = 3 s. Express your answer using three significant figures. Enter positive value if the angular velocity is clockwise and negative value if the angular velocity is counterclockwise. |
Solution
When t = 3 sec
The angular velocity of A = 20x3 + 35 = 95 rad/sec
clearly, D = B ,, since they are mounted on same shaft
Considering the fact that the velocity of belt will remain constant for the entire body of the belt. therefore the velocity of belt on the tip of pulley A must be same as the velocity of the belt on the tip of pully D
which implies , (r)A = (r)D
hence we get :
D /A = rA / rD = 75 / 25 = 3
D = A *3 = 95*3 = 285 rad / sec
B =D = 285 rad/sec
Now, C / B = rB / rC = 100 / 50 = 2
C = B x 2 = 285*2=570 rad / sec
