1. 11R1 Exam Revision LO: To review the topics for the February exam.
Thursday, 23 May 2019
Calculations involving percentages:
Calculate 2% of 50 g.
Calculate 2% of kg.
Calculate the percentage of people who are above 6ft if 7 out of 19 people are.
Calculate the total number of people if 3% of people are represented by 9 people.
Calculate the percentage equivalent of 15 out of
S & C: Calculate the total number if 3% represents by

2. Plotting Data

3. Determining uncertainty in data

4. Standard Form Calculations involving standard form:
1.2 x 103  1,200
1.2 x 10-3 
Calculations involving standard form:
Calculate 2.35 x 107.
Calculate 2.35 x 10-1.
Rewrite in standard form 1,000,000.
Rewrite in standard form 8,987,325.
Calculate x 10-6.
S & C: Rewrite in standard form

5. Rearranging equations
Rearrange A = B x C to make C the subject.
Rearrange A/B = C to make A the subject.
Rearrange A/B = C to make B the subject.
Rearrange Energy = mass x SHC x temp. ch. to make SHC the subject.
Rearrange KE = ½ x mass x velocity2 to make V the subject.

6. Forces To log on to Doddle: Institution: Ralph Thoresby
Institution: Ralph Thoresby
Username: fullname14 (the year you started Y7)
Password: ralph

7. Forces Scalar & Vector Quantities Contact & Non-Contact Forces
Gravity & Weight
Resultant Forces
Work Done & Energy Transfers
Elasticity (Force & PE)
Distance & Displacement
Speed
Velocity
DT Graphs
Acceleration
VT Graphs
Newton I – III
Stopping Distance – Thinking Distance & Braking Distance
Momentum

8. Scalar & Vectors

9. The larger the arrow, the larger the force.
Forces are pushes, pulls or turning forces acting on objects…measured in Newtons (N)
The larger the arrow, the larger the force.
Unbalanced (resultant) forces changes speed, direction or both (velocity)…
Reaction force
Tension
Lift
Draw forces from centre of object
Upthrust
Reaction
Gravity

10. g = 10N/kg on Earth…
E.g.
Mass = 70kg
g = 1.5N/kg
Weight = ?
Weight = 70 x 1.5
= 105 N

11. Work Done = Force x Distance
The force in a vertical direction = weight (mass x g) J N m
Effort, but no work done (with respect to holding the books)
W.D. = 50 x 12 = 600 J
No movement in the direction of the force, then no work done.
Work done Example 2
g = 10N/kg
Work done Example 3
A climber has a weight of 800N and climbs up 50m. What is the work done?
Clue! Weight = force
W.D. = 800 x 50 = 40,000 J
Clue! Mass does not equal force…
W.D. = (55 + 2) x 10 x 5 = 2850 J

12. Distance-Time (DT) Graphs
Speed = Distance = Change in Y = Gradient
Time Change in X

13. Velocity-Time (VT) Graphs
Acceleration = Velocity = Change in Y = Gradient
Time Change in X

14. Springs store elastic potential energy…
Hooke's Law
F = k × e
F is the force in newtons, N
k is the 'spring constant' in newtons per metre, N/m
e is the extension in metres, m
An elastic object such as a spring stores elastic potential energy when stretched or squashed.
The extension of an elastic object is directly proportional to the force applied.
Potential Energy

15. Newton’s Laws of Motion
Newton’s First Law
Newton’s Second Law
Newton’s Third Law

16. stopping distance = thinking distance + braking distance

17. Momentum Kg m/s kg m/s Momentum = Mass x Velocity
Momentum before = Momentum after

18. Forces Learning Check What is the unit of force?
What is a resultant force and what does it do?
Draw the forces on a ball speeding up as it falls.
Draw the forces on an aeroplane in steady flight.
Resolve the forces for a stone shoved off a cliff with a horizontal force of 20N if gravity is 10N (assume no air resistance).
Newtons (N)
Overall force. Changes speed, direction or both (changes velocity).
On next slide

19. Springs Learning Check
What is Hooke’s law?
What do we mean by ‘spring extension’?
A spring is stretched by 5cm by a weight. How much will two springs fastened side by side be stretched by?
Calculate the force need to stretch a spring by 20cm if the spring constant is 2N/m.
Calculate the energy stored in the same spring if stretched to 30cm.
F = k e (‘stretch’ is proportional to applied force).
The amount of stretch/increase in length.
2.5cm for two side-by-side springs.
F = k e cm = 0.2m = 2 x 0.2 = 0.4N
Energy = 0.5 k x cm = 0.3m = 0.5 x 2 x 0.32 = 0.09J

20. Work Done (W.D.) Learning Check
What is the equation for work done?
What is the work done for a force of 50N moving 50cm.
Calculate W.D. for a climber of weight 300N climbing up 5m of rock.
Calculate W.D. for a climber of mass 50kg (g = 10N/kg) climbing 75cm vertically.
Calculate the W.D. for a person holding 20kg of books for 10 minutes.
W.D. = force x distance
W.D. = f d = 50x0.5 = 25J
W.D. = 300x5 = 1500J
W.D. = 50x10x0.75 = 350J
Zero, as no movement mentioned.

21. Waves To log on to Doddle: Institution: Ralph Thoresby
Institution: Ralph Thoresby
Username: fullname14 (the year you started Y7)
Password: ralph

22. Waves Transverse & Longitudinal Waves (Labelling)
Wave Equation & Period
EM Spectrum (Uses & Dangers)
Radio Waves & Aerials

23. Transverse & Longitudinal Waves
Transverse Wave

24. Refraction
Part of a wavefront enters the water (or any denser material like glass) and slows down while the rest of the wavefront stays at the same speed and angle…

25. Wave Speed = Frequency x Wavelength
Wave Equation & Period
Period = 1/Frequency
Wave Speed = Frequency x Wavelength
m/s Hz m
Example 2:
Wave speed = 2m/s, frequency = 0.5Hz. What is the wavelength?
2 = 0.5 x ?  2/0.5 = ? = 4m

26. EM Spectrum (Uses & Dangers)
Microwaves
Infrared UV
X-rays
Gamma rays
Internal tissue heating
Skin burns
Ionising radiation so can cause cancer in low doses and kill cells in high doses.

27. Radio Waves & Aerials

28. Magnetism & Electromagnetism
To log on to Doddle:
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Password: ralph

29. Magnetism & Electromagnetism
Magnetic Poles & Fields (Bar & Solenoid)
Electromagnets (Variables & Uses)
Fleming’s LHR
Electric Motor & Fleming’s LHR

30. Magnetic Poles & Fields (Bar & Solenoid)
Bar magnet
Solenoid

31. Electromagnets (Variables & Uses)
What affects the strength of an electromagnet?
Or a higher current!

32. Fleming’s LHR

33. Electric Motor & Fleming’s LHR2. 1. 3.
Can you apply the rule to each situation to get the same result?