Resultant forces change the velocity of an object and/or change its shape.  Being able to make calculations about these changes allows us to design the thousands of machines we use every day.  So let's find out how it works....

Specification links:

• Set 1 - Sections  4.5.3  & 4.5.6

• Set2&3 - Sections 6.4.3 & 6.5.4 

Task 1b: Listen to the podcast to get an overview of the topic:

Task 2b: Note notes that:

• Define resultant force

• Explain how to calculate a resultant force

• Give the formula for calculating resultant force

Set 1&2:

• Define inertia

• Define inertial mass

Task 2c: Complete and then self mark the exam questions

Task 3b: Make notes that:

• Define the:

  • Independent variable,

  • Dependent variable,

  • Control variables.

• Explain how to carry out the experiment.

• Sketch a graph of the results and explain how they prove Newton's second law

• Explain why the calculated mass of the equipment is greater than the actual mass.

• Suggest a way to improve the experiment to reduce the size of this error.

Task 3c:  Complete the exam question

Task 4b: Make notes that:

• Explain the difference between mass and weight

• Give the formula that relates mass and weight

• Describe the forces acting on a falling object

• Explain how 

• Define and explain terminal velocity

Task 4d:  Watch the video then draw force diagrams showing the size of the forces acting on the skydiver:

• Just after leaving the plane

• In freefall

• Just after the parachute has opened

• Just before touching the ground

Task 4e: Complete the progress check

Task 5b: Make notes that:

• List the forces acting when a vehicle is in motion.

• Define:

  • Stopping distance

  • Thinking distance

  • Braking distance

• Explain what affects the stopping distance of a vehicle.

• Describe the problems harsh braking can cause

Task 6c:  Make notes that:

• Give the unit for momentum

• Give the equation for momentum

• Define conservation of momentum

Task 6e:  Complete and mark the exam questions

Task 7b:  Make notes that:

• Define  momentum

• Give a method to calculate momentum.

• Complete the calculation cartoons on slide 16

Task 7c:  Complete and mark the exam questions

Task 8b:  Make notes that:

• Give the equation that includes force, change in momentum and time.

• Define  impact force.

• Explain safety features to lower the impact force

Task 8c:  Complete the impact forces worksheet

Task 9c:

• Watch the video

• Describe a method for investigating how the force on a spring affects its extension

• Use the simulation to investigate the relationship between spring constant, fore applied and displacement.

• Explain how to calculate the spring constant from the results of this experiment

Complete the quiz for this unit to make sure you have understood it

Trilogy exam questions: Easy   Medium   Hard

GCSE Physics exam questions:   Easy   Medium   Hard