OAR OAR Mechanical Reasoning 3

Question 1

A car engine produces 200 foot-pounds of torque at 3,000 RPM. What is the horsepower output? (1 HP = 5,252 ft-lb/min at 1 RPM)

Accepted Answer

About 114 HP

Answer

HP = (Torque × RPM) / 5,252 = (200 × 3,000) / 5,252 ≈ 114 HP.

Question 2

A fixed pulley system redirects force but offers no mechanical advantage. Adding a second movable pulley creates a system with a mechanical advantage of:

Accepted Answer

2

Answer

A single movable pulley halves the required effort force, giving a mechanical advantage of 2.

Question 3

Which material expands the MOST when heated to the same temperature increase?

Accepted Answer

Aluminum

Answer

Aluminum has a higher coefficient of thermal expansion than steel, concrete, or glass.

Question 4

A ball is thrown horizontally from a cliff at 20 m/s. Ignoring air resistance, how does its horizontal velocity change as it falls?

Accepted Answer

It remains constant

Answer

Gravity acts only vertically, so horizontal velocity stays constant in the absence of air resistance.

Question 5

A pipe joint is leaking because the threads are stripped. The BEST immediate repair approach is to:

Accepted Answer

Wrap Teflon tape over the threads and retighten

Answer

Teflon tape fills thread gaps and creates a pressure-resistant seal on threaded pipe fittings.

OAR Test Practice Test

OAR Test Practice Test

OAR OAR Mechanical Reasoning 3