Physics and Simple Machines Flashcards
7 cards from real SIFT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Physics and Simple Machines flashcards as text
A screw advances 2 mm per rotation. If a screwdriver handle has a radius of 4 cm, what is the mechanical advantage? (Use MA = 2πr / pitch)
Answer: Approximately 126
MA = 2π × 0.04 m / 0.002 m ≈ 125.7, approximately 126.
An object moving in a circle at constant speed is experiencing which type of acceleration?
Answer: Centripetal acceleration toward the center
Even at constant speed, circular motion requires centripetal acceleration directed toward the center to change the direction of velocity.
A third-class lever always has a mechanical advantage that is:
Answer: Less than 1
In a third-class lever, effort is applied between the fulcrum and load, always resulting in a mechanical advantage less than 1, though range of motion increases.
Which law of motion states that for every action there is an equal and opposite reaction?
Answer: Newton's Third Law
Newton's Third Law states that forces always come in equal and opposite action-reaction pairs.
The unit of work in the SI system is the:
Answer: Joule
Work is measured in joules (J), where 1 J = 1 N·m, the energy transferred when a 1-newton force moves an object 1 meter.
A movable pulley provides a mechanical advantage of 2 because:
Answer: Two rope segments support the load
A movable pulley has two rope segments pulling upward on the load, so each segment supports half the load, giving MA = 2.
If friction is present in a simple machine, its actual mechanical advantage compared to its ideal mechanical advantage is:
Answer: Lower
Friction wastes energy as heat, requiring more input effort than the ideal frictionless case, so actual MA is always lower than ideal MA.