SIFT Mechanical Comprehension 3

Question 1

An object requires 300 J of work to move 15 meters. What is the average force applied?

Accepted Answer

20 N

Answer

5 N

Answer

15 N

Answer

4,500 N

Question 2

A ball is thrown vertically upward. At the peak of its trajectory, what is its velocity?

Accepted Answer

Zero

Answer

Maximum positive velocity

Answer

Maximum negative velocity

Answer

Equal to its initial velocity

Question 3

What does a 'circuit breaker' do in an electrical system?

Accepted Answer

Automatically interrupts current flow when it exceeds a safe limit

Answer

Increases voltage when demand spikes

Answer

Converts AC power to DC power

Answer

Stores excess electrical charge

Question 4

What type of stress does a bolt in a bolted joint primarily experience when the joint resists forces that try to slide the two halves sideways?

Accepted Answer

Shear stress

Answer

Tensile stress

Answer

Compressive stress

Answer

Bending stress

Question 5

What is the relationship between wavelength and frequency in a wave?

Accepted Answer

Wavelength and frequency are inversely proportional at constant wave speed

Answer

Wavelength and frequency are directly proportional — both increase together

Answer

Wavelength and frequency are independent — they don't affect each other

Answer

Longer wavelengths always indicate higher frequencies

Question 6

A 60 W light bulb runs for 5 hours. How much electrical energy does it consume in kilowatt-hours?

Accepted Answer

0.3 kWh

Answer

0.03 kWh

Answer

3 kWh

Answer

300 kWh