Forces & Elasticity (AQA GCSE Physics): Exam Questions

A newton meter, as shown in Figure 1, consists of a point connected to a metal spring.

When a force is applied to the spring, the spring stretches, and the point moves along the scale to the maximum reading.

Figure 1

Use the information provided in the diagram to calculate the spring constant of the spring.

A student wishes to carry out an investigation to measure the spring constant of a metal spring.

Plan a method that the student could use.

Your answer should include detail of how accurate measurements may be taken and may also include a labelled diagram

The table below gives the results obtained by the student.

The student finds that after stretching, the spring does not return to its original length.

Plot a graph of force (y-axis) against extension (x-axis) on the grid below.

Draw the position of the elastic limit on the graph, using an X.

Give your reason for choosing this point.

The student has made an error whilst calculating some of the results.

Suggest what the error was and how the results could be corrected.

Use the graph to calculate the spring constant of the metal spring.

The student decided to repeat the experiment using a double spring set up, as shown in Figure 2

Figure 2

Draw a line on your original graph showing the results you would expect the student to get.

You should assume that the initial extension of the springs is the same as with the original experiment.

Explain how the elastic limit of the double spring will compare with the original spring.

Figure 3 shows three different stages in a bungee jump.

Figure 3

Stage 1: The jumper is stationary and the bungee cord is slack

Stage 2: The bungee cord has no slack, but is not yet exerting a force on the jumper.

Stage 3: The jumper is at the lowest point and has temporarily stopped moving.

Describe the change in energy stores that occur between stage 1 and stage 3.

Calculate the change in energy in the jumper’s gravitational potential store between stage 1 and stage 2.

The jumper has a mass of 60.0 kg (assume that the mass of the bungee cord is negligible).

Gravitational field strength = 9.8 N/kg

Determine the energy in the jumper’s kinetic store at stage 2.

Calculate the speed of the bungee jumper at stage 2.

After reaching stage 2, the bungee cord starts to stretch, exerting an upwards force on the jumper which eventually brings the jumper to a stop at stage 3.

Between stage 1 and stage 3 the jumper’s gravitational energy store decreases by a total of 18 000 joules.

Determine the energy in the bungee’s elastic store at stage 3.

Calculate the extension of the bungee cord at stage 3.

Using an appropriate equation from the Physics equation sheet, calculate the spring constant of the bungee cord.

You may assume that the bungee cord behaves like a perfect spring.

Use your answers to (f) and (g) to calculate the force exerted by the bungee cord on the jumper at stage 3.

At stage 3 the jumper's spine stretches a small but safe amount.

Explain why the jumper's spine stretches.

A student investigates how the extension of a spring changes when different forces are applied.

The student adds masses to the spring and measures the extension.

Table 1 shows the student’s results:

Table 1

What is meant by the independent variable?

Tick (✓) one box.

Suggest a control variable for this investigation.

Figure 4 shows a graph of the results.

Figure 6

The points for 0.0 N, 1.0 N, 2.0 N and 3.0 N have already been plotted.

Plot the remaining results from Table 1 on Figure 4.

Draw a line of best fit.

State the relationship between force and extension as shown by the graph.

Calculate the spring constant of the spring.

Use the equation:

Give your answer in units of N/cm.

Before adding any weights, the student noticed that the ruler reading for the bottom of the spring was not zero.

The student did not adjust the ruler.

Explain what type of error would this cause in the results and how the student could correct this error using the data.

A different spring is stretched.

The spring constant of this spring is 40 N/m. The extension of the spring is 0.20 m.

Calculate the elastic potential energy stored in the spring.

Use the equation:

The student adds more masses to the spring.

The spring reaches its elastic limit.

Explain what happens to the spring when the elastic limit is exceeded.

Give one safety precaution the student should take during this investigation.

A student investigated the relationship between the force applied to a spring and the extension of the spring.

The student used a clamp stand, a spring, a metre rule, and slotted masses.

Describe one technique the student could have used to improve the accuracy of the extension measurements.

The student added masses until the spring was inelastically deformed.

How would the student know that the spring had been inelastically deformed?

The student repeated the investigation with a different spring.

When a force of 4.5 N is applied, the extension of the spring is 0.060 m.

Calculate the spring constant of the spring.

Use the Physics Equations Sheet.

Calculate the elastic potential energy stored in the spring when the extension is 0.060 m.

Use the Physics Equations Sheet.

The student compressed the spring by 0.060 m and used it to launch a toy car horizontally across a desk.

mass of toy car = 0.015 kg.

Calculate the maximum speed of the toy car just after it is launched.

Use the Physics Equations Sheet.

A group of physics students are investigating force and extension of a spring.

One student obtained the results shown in Table 1.

Table 1

As the teacher came around to check the student's data, the teacher asked the student to think about why the extension data is not increasing.

Identify the mistake the student has made in their data analysis process.

Another student plotted their graph, but the shape of the curve was different to everybody else's. 

Figure 1 shows the student's graph.

Figure 1

Suggest what the student did to produce the graph shown in Figure 1.

Another student extrapolated their graph as shown in Figure 2.

Figure 2

What is the significance of the point marked X?

Tick (✓) one box.   

Figure 1 shows a force-extension graph for a spring with a spring constant k.

Figure 1

Draw a line on Figure 1 for a spring with a higher value of k.

A force of 6.0 N stretches a spring by 3.0 cm.

Calculate the extension of the spring when a force of 4.5 N is applied.

Give your answer in cm to 2 significant figures.

   Extension = .................................... cm

A student plotted a force-extension graph for a spring of spring constant k. 

Figure 1 shows the graph they plotted.

Figure 1

The student has labelled one of the data points as anomalous. 

Justify whether you agree with the student.

For the spring used in part (a), calculate the work done on the spring when a 3 N force is applied.

Give your answer in the appropriate units.

   Work done = ............................. Units = ...............................