A-LevelPhysicsPhysical quantities and units9702/22 · Feb/Mar 2020 · Q16 Marks
Length, mass and temperature are all SI base quantities. State two other SI base quantities.
- (a)Length, mass and temperature are all SI base quantities. State two other SI base quantities.[2]
- (b)(i)The acceleration of free fall g may be determined from an oscillating pendulum using the equation g = 4π²l –––– T² where l is the length of the pendulum and T is the period of oscillation. In an experiment, the measured values for an oscillating pendulum are l = 1.50m ± 2% and T = 2.48s ± 3%. Calculate the acceleration of free fall g.[1]
- (b)(ii)Determine the percentage uncertainty in g.[2]
- (b)(iii)Use your answers in (b)(i) and (b)(ii) to determine the absolute uncertainty of the calculated value of g.[1]
Mark scheme
Marking points from the official mark scheme (Feb/Mar 2020). The mark or mark type is shown in brackets.
- B2 time
- B2 (electric) current
- B2 allow amount of substance
- B2 allow luminous intensity
- B2 any two of the above quantities, 1 mark each
- C1 g = (4π² × 1.50) / (2.48²)
- A1 = 9.63 m s⁻²
- C1 percentage uncertainty = 2 + (3 × 2)
- C1 or fraction uncertainty = 0.02 + (0.03 × 2)
- A1 percentage uncertainty = 8%
- A1 absolute uncertainty = 0.08 x 9.6
- A1 = 0.8 m s⁻²
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →