ADF ADF Mechanical Reasoning 2

Question 1

A force of 10 N is applied at the rim of a wheel with a radius of 0.5 m. What is the torque produced?

Accepted Answer

5 Nm

Answer

Torque = Force × perpendicular distance from pivot; 10 N × 0.5 m = 5 Nm.

Question 2

Two objects of different mass are dropped simultaneously from the same height in a perfect vacuum. What happens?

Accepted Answer

Both objects hit the ground at the same time

Answer

In a vacuum, gravitational acceleration is equal for all objects regardless of mass, so both objects reach the ground simultaneously.

Question 3

According to Pascal's Law, what happens to pressure when force is applied to a confined fluid?

Accepted Answer

Pressure is transmitted equally throughout the fluid

Answer

Pascal's Law states that pressure applied to an enclosed, incompressible fluid is transmitted undiminished in all directions throughout the fluid.

Question 4

A bolt has a thread pitch of 2 mm. How many complete turns are required to advance it 10 mm into a surface?

Accepted Answer

5 turns

Answer

Turns required = distance ÷ pitch; 10 mm ÷ 2 mm per turn = 5 complete turns.

Question 5

In a circuit, if resistance doubles while voltage remains constant, what happens to the current?

Accepted Answer

Current halves

Answer

Ohm's Law states I = V ÷ R; if R doubles and V is constant, current I is halved.

ADF - Australian Defence Force Practice Test