SIFT Physics and Simple Machines 2

Question 1

A pulley system has a mechanical advantage of 4. If a 200 N load is lifted, how much effort force is required (ignoring friction)?

Accepted Answer

50 N

Answer

Mechanical advantage = Load / Effort, so Effort = 200 N / 4 = 50 N.

Question 2

Which type of lever has the fulcrum located between the effort and the load?

Accepted Answer

First-class lever

Answer

In a first-class lever, the fulcrum is positioned between the effort force and the load.

Question 3

An inclined plane reduces the force needed to lift an object by increasing which quantity?

Accepted Answer

The distance over which force is applied

Answer

An inclined plane trades increased distance for reduced force, allowing the same work to be done with less effort.

Question 4

A wheel and axle has a wheel radius of 30 cm and an axle radius of 5 cm. What is its mechanical advantage?

Accepted Answer

6

Answer

MA of a wheel and axle = wheel radius / axle radius = 30 / 5 = 6.

Question 5

Newton's Second Law states that force equals mass times acceleration. If a 10 kg object accelerates at 3 m/s², what net force acts on it?

Accepted Answer

30 N

Answer

F = ma = 10 kg × 3 m/s² = 30 N.

SIFT Exam Practice Test