Revision Test 1.3

What does Newton’s first law of motion state?

What type of load is applied evenly over the entire area or length of a beam?

(a)  

What is a bending moment?

Answer explanation

Correct if the answer explains that a bending moment is the internal moment that causes a beam or structural element to bend, typically measured in units of force times distance (e.g., Nm or lb-ft). It results from external loads, reactions, or moments applied to the structure.

What is the formula for mechanical work?

Answer explanation

Correct if the formula for mechanical work is given as W = F d cos(θ), where W is work, F is force, d is displacement, and θ is the angle between force and displacement.

State Newton’s third law of motion.

Answer explanation

Correct: Newton's third law states that for every action, there is an equal and opposite reaction. Incorrect: Any deviation from this definition.

A motor vehicle has a mass of 1500 kg. Calculate the engine force needed to produce an acceleration of 2.5 m/s².

Answer explanation

Correct. The engine force is calculated using F = ma. With mass 1500 kg and acceleration 2.5 m/s², the force is 3750 N. The calculation follows Newton's second law accurately.

A machine tool is suffering from excessive friction with a workpiece. Explain how this could affect the condition of the tool.

Answer explanation

Correct if it explains that excessive friction can lead to increased wear, heat generation, and potential damage to the tool, reducing its lifespan and efficiency.

Explain the difference between a point load and a uniformly distributed load on a beam.

Answer explanation

Correct if the answer explains that a point load is concentrated at a single point on a beam, while a uniformly distributed load is spread evenly across a length of the beam.

A box of materials is pushed with a force of 200 N for a distance of 15 m. Calculate the work done to the box.

Answer explanation

Correct. The work done is calculated using the formula Work = Force x Distance. Here, Work = 200 N x 15 m = 3000 J (joules). The calculation is accurate and follows the correct formula for work done in physics.

The work done to move a crate is 50 J and the time taken to do this is 20 seconds. Calculate the power needed to move the crate.

Answer explanation

Correct. Power is calculated as work done divided by time. Power = 50 J / 20 s = 2.5 W. The answer is correct as the calculation follows the formula for power.