SIFT Physics and Simple Machines 3

Question 1

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)

Accepted Answer

Approximately 126

Answer

MA = 2π × 0.04 m / 0.002 m ≈ 125.7, approximately 126.

Question 2

An object moving in a circle at constant speed is experiencing which type of acceleration?

Accepted Answer

Centripetal acceleration toward the center

Answer

Even at constant speed, circular motion requires centripetal acceleration directed toward the center to change the direction of velocity.

Question 3

A third-class lever always has a mechanical advantage that is:

Accepted Answer

Less than 1

Answer

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.

Question 4

Which law of motion states that for every action there is an equal and opposite reaction?

Accepted Answer

Newton's Third Law

Answer

Newton's Third Law states that forces always come in equal and opposite action-reaction pairs.

Question 5

The unit of work in the SI system is the:

Accepted Answer

Joule

Answer

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.

SIFT Exam Practice Test

SIFT Exam Practice Test

SIFT Physics and Simple Machines 3