Pulleys and Levers Flashcards
7 cards from real Bennett Mechanical Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pulleys and Levers flashcards as text
A nutcracker that pivots at the hinged end is which class of lever?
Answer: Second-class lever
A nutcracker is a second-class lever with the load (nut) between the fulcrum and the effort.
A block and tackle with 5 supporting rope segments lifts a 500 lb load. What effort is needed (ignoring friction)?
Answer: 100 lb
With a mechanical advantage of 5, effort equals 500 ÷ 5 = 100 lb.
What happens to the force needed as you move the fulcrum closer to the load on a lever?
Answer: Less force is needed
Moving the fulcrum closer to the load lengthens the effort arm, reducing the force required.
A wheelbarrow lets a worker lift a heavy load with less effort because it is a:
Answer: Second-class lever
A wheelbarrow is a second-class lever with the wheel as the fulcrum and the load between it and the handles.
If a movable pulley gives a mechanical advantage of 2, how far must you pull the rope to raise the load 3 ft?
Answer: 6 ft
With a mechanical advantage of 2, you pull twice the load distance, so 3 × 2 = 6 ft.
Which simple machine is a pulley actually a variation of?
Answer: A lever (wheel rotating about an axle)
A pulley acts like a continuous lever, with its center axle as the fulcrum.
A lever requires 40 lb of effort to lift an 80 lb load. If friction is added, the real effort needed will be:
Answer: More than 40 lb
Friction always increases the actual effort required above the ideal frictionless value.