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 pair of scissors is an example of which combination of simple machines?
Answer: Two first-class levers
Scissors combine two first-class levers pivoting around a central fulcrum.
Which lever class always produces a mechanical advantage less than 1?
Answer: Third-class lever
In a third-class lever the effort arm is shorter than the load arm, giving a mechanical advantage below 1 but more speed.
Two pulleys are arranged so one is fixed and one is movable. What is the mechanical advantage?
Answer: 2
One fixed plus one movable pulley gives a mechanical advantage of 2 from two supporting rope segments.
On a balanced seesaw, a 100 lb child sits 3 ft from the pivot. Where must a 60 lb child sit to balance it?
Answer: 5 ft from the pivot
Balance requires equal moments: 100 × 3 = 300, so 300 ÷ 60 = 5 ft.
A bottle opener that pivots against the cap edge is which class of lever?
Answer: Second-class lever
A bottle opener has the load (cap) between the fulcrum and the effort, making it a second-class lever.
If you increase the length of the effort arm on a lever while keeping the load arm the same, the mechanical advantage will:
Answer: Increase
A longer effort arm relative to the load arm increases mechanical advantage.
In a block and tackle, what is the trade-off for gaining mechanical advantage?
Answer: You must pull more rope length
Greater mechanical advantage in a block and tackle requires pulling proportionally more rope.