1. Newtons law In this section you will
be introduced to Newton’s second law of
motion
look at how Newton’s law can be investigated
use the equation to solve problems

2. Newtons law Isaac Newton said that:-
An object will remain stationary or move at a
unless a resultant
acts on it.

3. Newtons law Isaac Newton said that:-
An object will remain stationary or move at a
constant velocity unless a resultant force
acts on it.

4. EXPERIMENT 1
The air track removes the force of friction.
The only force will be exerted by the weights.
You will see how increasing the force on the
glider affects it’s acceleration

5. Investigating Newton’s law
GLIDER
Bench
Bench
FORCE
ACCEL
0.1N
0.5m/s 2

6. Investigating Newton’s law
GLIDER
Bench
Bench
FORCE
ACCEL
0.2N
1.0m/s 2

7. Investigating Newton’s law
GLIDER
Bench
Bench
FORCE
ACCEL
0.3N
1.5m/s 2

8. Investigating Newton’s law
GLIDER
Bench
Bench
FORCE
ACCEL
0.4N
2.0m/s 2

9. Force Bench Weight Force(N) Acceleration(m/s ) 0.1 0.5 0.2 0.3 0.4 2
GLIDER
Bench
10g
Mass
holder
Bench
Weight
Force(N)
Acceleration(m/s )
0.1
0.5
0.2
0.3
0.4 2
Fill in the missing numbers
To show you understand the pattern
(trend)
Click to
check your
answers

10. Force Bench Weight Force(N) Acceleration(m/s ) 0.1 0.5 0.2 1 0.3 1.5
GLIDER
Bench
10g
Mass
holder
Bench
Weight
Force(N)
Acceleration(m/s )
0.1
0.5
0.2 1
0.3
1.5
0.4 2 2

11. EXPERIMENT 2
The air track removes the force of friction.
The only force will be exerted by the weights.
You will see how increasing the mass of the
glider affects it’s acceleration

12. Investigating Newton’s law
GLIDER
Bench
Bench
MASS
ACCEL
200g
2m/s 2

13. Investigating Newton’s law
GLIDER
Bench
Bench
MASS
ACCEL
250g
1.75m/s 2

14. Investigating Newton’s law
GLIDER
Bench
Bench
MASS
ACCEL
300g
1.5m/s 2

15. Investigating Newton’s law
GLIDER
Bench
Bench
MASS
ACCEL
350g
1.25m/s 2

16. Investigating Newton’s law
GLIDER
Bench
Bench
MASS
ACCEL
400g
1.00m/s 2

17. Force Bench Weight Mass (g) Acceleration (m/s ) 200 2 250 1.75 300 350
GLIDER
Bench
10g
Mass
holder
Bench
Weight
Mass (g)
Acceleration
(m/s )
200 2
250
1.75
300
350
400 2
Click to
check your
answers
Fill in the missing numbers
To show you understand the
pattern (trend)

18. Force Bench Weight Mass (g) Acceleration (m/s ) 200 2 250 1.75 300 1.5
GLIDER
Bench
10g
Mass
holder
Bench
Weight
Mass (g)
Acceleration
(m/s )
200 2
250
1.75
300
1.5
350
1.25
400 1 2

19. SUMMARY OF RESULTS

20. Force Bench Weight Force(N) Acceleration(m/s ) 0.1 0.5 0.2 1 0.3 1.5
GLIDER
Bench
10g
Mass
holder
Bench
Weight
Force(N)
Acceleration(m/s )
0.1
0.5
0.2 1
0.3
1.5
0.4 2
Mass (g)
Acceleration
(m/s )
200 2
250
1.75
300
1.5
350
1.25
400 1 2 2

21. More force on the glider causes acceleration.
Summary
More force on the glider causes
acceleration.
If the mass of the glider is the
acceleration is reduced
These results are summarised by the equation
force = mass x acceleration
F = m x a
Complete the
Missing words
Click to see
answers
(N)
(m/s ) 2
(kg)

22. More force on the glider causes more acceleration.
Summary
More force on the glider causes more
acceleration.
If the mass of the glider is increased the
acceleration is reduced
These results are summarised by the equation
Resultant force = mass x acceleration
F = m x a
(N)
(m/s ) 2
(kg)

23. 1 A car has a thrust of 1200N and a mass of
Questions
1 A car has a thrust of 1200N and a mass of
800kg. Work out it’s acceleration
a = =
2 A car brakes with a force of 800N and has a
deceleration of 2m/s . Work out the mass of
this car.
3 A car of mass 500kg accelerates at 1.5m/s
work out the thrust force of the engine
4 A car with a thrust of 1000N has a mass of
800kg. If the drag force is 200N work out the
acceleration.
Click to see answers : 2
m = = : 2
F = X =
a = = :

24. 1 A car has a thrust of 1200N and a mass of
Questions
1 A car has a thrust of 1200N and a mass of
800kg. Work out it’s acceleration
2 A car brakes with a force of 800N and has a
deceleration of 2m/s . Work out the mass of
this car.
3 A car of mass 500kg accelerates at 1.5m/s
work out the thrust force of the engine
4 A car with a thrust of 1000N has a mass of
800kg. If the drag force is 200N work out the
acceleration.
a = 1200N/800kg = 1.5m/s 2 2
m = 800N/2m/s = 400kg 2 2 2
F = 500N X 1.5m/s = 750N
a = (1000 – 200)/800 = 800/800=1m/s 2

25. A C B D No drag force Mass of person = 70kg Work out the accelerations
TERMINAL
VELOCITY C
700 N D
700 N
Gravity
Air friction
700 N
700 N
Equation to use is a=F/m (where F is the resultant force)
a = = m/s 2
a = = m/s 2
a = = m/s 2
a = = m/s 2 A C B D
Click to see
answers

26. Work out the accelerations 210 N
No drag
force
Mass of person = 70kg
Work out the accelerations
210 N
490 N
700 N A B
TERMINAL
VELOCITY C
700 N D
700 N
Answers
A = 10m/s
B = 7m/s
C = 3m/s
D = 0m/s (terminal velocity) 2 2
700 N
700 N 2 2

27. END