1. To introduce F=ma Recap our test from before half term
Carry out an experiment to investigate the relationship between acceleration and mass, acceleration and force
Start solving problems involving F=ma

2. Recap our test

3. Linear air track experiment
Investigate the relationship between acceleration and force
Investigate the relationship between acceleration and mass
Plot a graph
Draw conclusions

4. From your graph you have found
a ∝ F
a ∝ 1 𝑚
Thus a ∝ 𝐹 𝑚 , and choosing an appropriate constant
a= 𝐹 𝑚 , and F = ma.
Resultant force = mass x acceleration

5. Key definitions Define resultant force Define the newton
A resultant force is a single force which has the same effect as the sum of all the forces acting on a body
Define the newton
1 newton is the force required to accelerate an object of mass 1kg by 1ms-2

6. Weight
Weight in N = mass x acceleration due to gravity
Weight = mg

7. Example
A go kart has a rocket attached to it of mass 78kg (with driver). The go kart is travelling at a constant speed of 4ms-1, at which point the rocket fires and the go kart experiences a driving force of 450N and drag forces of 280N. Calculate
The resultant force acting on the go-kart
The acceleration of the go-kart
The final speed of the go-kart if it continues to accelerate at this rate for 5 seconds

8. You try
Questions from the sheet

9. Homework
Make notes on the types of force from page 51 of your text book ready for the lesson tomorrow, include a diagram.