A Level Physics Aqa Already Passed

Percentage Uncertainty {Ans: (Absolute Uncertainty/Mean Value) x 100}Molar Mass (Mr) {Ans: The mass of one mole of a substance.}Precision of a Measurement {Ans: Precise measurements are very close to mean value, little variation. Precision *only* depends on random errors and gives *no indication* of how close the results are to the true/accepted value.}Beta-plus Decay {Ans: When positrons are emitted by unstable proton-rich nuclei along with a neutrino. This decreases the atomic number by 1.}Time Dilation {Ans: When the elapsed time appears to be longer for a system that is moving faster than the observer.}Current {Ans: The movement of charged particles/charge carriers in a circuit. I = ∆Q/∆t Unit: amp, A}