1. Physical quantity equivalents mass1 Kg1000g 1g.001kg distance1mm0.001m 1cm0.01m 1m1000mm 1000 m 1km These are the “tricky” ones Pre-fixMultiplier nano(n)10 -9. 000000001 micro (μ)(μ) 10 -6. 000001 milli(m)10 -3. 001 kilo(k)10 3 1000 mega(M)10 6 1000000 giga(G)10 9 1000000000 If your quantity (number) has a prefix then you multiply the number part by the value of the prefix to get units. Example: 120kJ = 120 x 10 3 = 120,000 J Example: 350 mm = 350 x 10 -3 = 0.35 m If you have a number and you would like to use a prefix then you divide the number by the value of the prefix to get the Number with a Prefix Example: 120,000J = 120,000 ÷ 10 3 = 120kJExample: 0.35m = 0.35 ÷ 10 -3 = 350mm kg (kilogram) is the only SI unit that has a prefix - all the others don’t i.e. A (ampere) J (joule) m (metre) N (newton) s (second) V (volt) W (watt) Ω (ohm) kg (kilogram) is the only SI unit that has a prefix - all the others don’t i.e. A (ampere) J (joule) m (metre) N (newton) s (second) V (volt) W (watt) Ω (ohm)

2. Divide you page down the middle and label Before and After (collision). Draw a diagram! Write down your formulas Substitute values: Remember to look for stationary objects - their velocity is zero and that part of the equation goes away! Now let LHS (before) = RHS (after) Then solve for unknown value (i.e. what the question asked you to find) Note : the unit of momentum is kgm/s or kgms -1 Note : the formula for momentum is given as p=mv in the Data Booklet Use “u” for velocity before and use “v” for velocity after collision

3. Constant Velocity … (Newton’s 1 st Law) Constant Acceleration due to gravity Draw diagram or sketch List known and unknown quantities Draw line down centre of page On LHS write Horizontal On RHS write Vertical Constant Velocity Constant Acceleration Time (t) is common to both horizontal and vertical motion

4. Speed or Velocity (ms -1 ) time (s) acceleration constant speed deceleration constant speed Distance travelled = Area under graph NOTE: v > u gives acceleration; v < u gives deceleration or negative acceleration

5. Again, remember that V S = V 1 + V 2 … you don’t need to use formula 2 twice! Try to use formula 1 first. You need 3 of the 4 terms V1, V2, R1 or R2. (V S is not required) Use this formula if you can’t use formula 1. Look for V S in the question. Before you begin. Remember that V S = V 1 + V 2 Now write down what you know and don’t know !

6. The question will indicate whether the temperature (Thermistor) or light (LDR) is increasing or decreasing. Use this information to start your answer e.g “As the light level falls the resistance of the LDR increases …” The LDR or Thermistor may be placed here – you need to think how this affects step 2 LDR1 R2 Vs V2V2 Explain the Science of the LDR (L.U.R.D.) or Thermistor (T.U.R.D.) This could be any output device, e.g. relay, bell, buzzer etc. Explain How the Transistor works:- Switches ON at the threshold voltage 0.7 V for npn transistor 1.0 – 2.0 volts for MOSFET

7. Copy this from the Physics data booklet Read the question carefully and select two of the three terms (ratios) shown in the formula – you should end up with a simpler relationship containing two terms (ratios). Cross multiply to simplify then solve for the unknown term.. Transformers are not 100% efficient due to Heat loss Magnetising currents Sound (vibrations)

8. Cooling Curve Temperature(T) time(t) Gas Liquid Solid When material is cooling it gives off heat energy When its temperature is increasing the material is absorbing heat energy

9. LED numerical questions are usually worth three marks. The question usually gives the operational or working voltage of the LED … and the operational or operating current of the LED. Then it asks you to calculate R Vs R The current through R is the same as the operating current of the LED Remember to include unit Ω This is where you get the extra mark

10. If the question asks you to find a “half life” or “how long a sample takes to decay” or “the initial or final level of Activity” then it’s a good bet that you need a ………….. Activity (units) Time (units) Fill in the initial Activity Initial time = 0 0 Divide previous Activity by 2 Until you reach your Final Activity Add one ½ Life to previous time Until your reach your Final time To find the number of half lives – count the number of entries you have Made in the time row, but don’t count the first one (the zero value). You will get the Units from the question To find the Half Life divide the final time by the number of half lives

11. Initially Vc = Logic 0 (0V) Not gates inverts Logic to Logic 1 (5v) This is applied to top of R1 Capacitor charge up to Logic 1 (5v) Not gates inverts Logic to Logic 0 (0v) This is applied to top of R1 Capacitor discharges to Logic 0 (0v) The process repeats R1 Logic 0 = 0V Logic 1 = 5V Timing/ Frequency determined by R1 and C ½ mark