Principal: Mr. T. Power, B.A. H.D.E.
Vice Principal: Ms. F. Greene, B.A. H.D.E.

Junior Cert

SCIENCE > FORMULAS FOR THE JUNIOR CERT
Given is the twenty formulas that have appeared on the Junior Cert. The unit is given in brackets. Remember that if a mathematical question has six marks, three will go for the correct numerical answer and three for the correct unit.

Physics
1. Density (gcm^-3) = Mass / Volume
2. Weight (N) = Mass x Gravity
3. Speed (ms^-1) = Distance / Time
4. Acceleration (ms^-2) = (New Velocity - Old Velocity) / Time Taken To Change
5. Momentum (kgms^-1) = Mass x Velocity
6. Moment of a Force (Nm) = Force x Perpendicular Distance
7. Moments on the Left = Moments on the Right
8. Work (J) = Force x Distance
9. Pressure (Pascal) = Force / Area
10. Kelvin = ° Celsius + 273
11. Heat = Mass x Specific Heat Capacity x Change in Temperature
12. Velocity of a Wave (ms^-1) = Frequency x Wavelength
13. Number of Kilowatt-Hours (KWh or Units) = Number of Kilowatts x Number of Hours
14. Cost of Electricity = Number of Kilowatt-Hours x Cost per Unit
15. Voltage = Resistance x Current At Constant Temperature (Ohms Law)
16. Resistance () = Add The Resistances (Resistances in Series)
17. Power (W) = Voltage x Current

Applied Science
18. Voltage = Resistance x Current At Constant Temperature (Ohms Law)
19. Resistance = Add The Resistances (Resistances in Series)
20. Formula for a Transformer = V_p / V_s = N_p / N_s