Question

part 9 - mechanical comprehension instructions
when the belt moves in the direction shown, which pulleys turn clockwise?
a only 1
b only 2
c only 3
d both 1 and 2 only
e all of them
if e is your answer, click the next button. otherwise, select another answer.

Explanation:

To determine the direction of pulley rotation, we analyze the belt movement:

1. The belt moves towards Pulley 1 (as per the arrow). For Pulley 1, the belt's movement on its left - hand side (where the arrow is) will cause Pulley 1 to turn clockwise. This is because the belt's motion "pulls" the pulley in the clockwise direction at the point of contact.
2. Pulley 2: The belt is connected to Pulley 2. Since the belt is moving in a way that the part of the belt in contact with Pulley 2 will make Pulley 2 rotate clockwise. The direction of the belt's movement around Pulley 2 (considering the connection to Pulley 1 and Pulley 3) leads to a clockwise rotation for Pulley 2.
3. Pulley 3: The belt's movement around Pulley 3 is such that it will rotate counter - clockwise. The way the belt is looped around Pulley 3 (connected to Pulley 1 and Pulley 2) means that the force from the belt will make it turn in the opposite direction of Pulley 1 and Pulley 2.

So, Pulleys 1 and 2 turn clockwise.

Answer:

D. both 1 and 2 only