1. Forces 2nd Law and suvat
Extended problems

2. Starter: KUS objectives BAT Understand Newtons 3 laws
BAT Solve problems using Newtons 2nd law
BAT solve problems with moving objects using the suvat model
Starter: 2

3. The stone is modelled as a particle acceleration g is constant
WB9
A stone of mass 0.5 kg is released from rest on the surface of the water in the well.
Suggest a model
The stone is modelled as a particle
acceleration g is constant
resistance force due to the water is constant
There are no other forces
A stone of mass 0.5 kg is released from rest on the surface of the water in the well. It takes 2 seconds to reach the bottom of the well. Given that the water exerts a constant resistance of 2 N, find the depth of the well

4. WB9 solution
A stone of mass 0.5 kg is released from rest on the surface of the water in the well. It takes 2 seconds to reach the bottom of the well. Given that the water exerts a constant resistance of 2 N, find the depth of the well R W a
Draw a diagram:
2nd Law
Explain that the sledge is NOT moving up or down – only horizontally forward

5. WB10 Car
A car travels a distance of 32m along a straight road while uniformly accelerating from rest to 16 ms-1. By modelling the car as a particle find its acceleration.
Given that the mass of the car is 640 Kg, find the magnitude of the accelerating force.
What might the opposing forces be called? 5

6. 300 500g R Resultant Force down slope deceleration WB11
A car of mass 500 kg travelling at a constant speed of 25 ms-1 reaches a slope inclined at 300 to the horizontal. The resistance forces on the car travelling up the slope total 300 N.
The driver takes their foot off the acceleration pedal at the start of the slope
Find the distance travelled by the car before it comes to rest R
300
Resultant Force down slope
500g
deceleration 6

7. One thing to improve is –
KUS objectives
Understand Newtons 3 laws
Solve problems using Newtons 2nd law
solve problems with moving objects using suvat model
self-assess
One thing learned is –
One thing to improve is –

8. END