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Grade 9 · Physics

Grade 9 Physics diagnostic

14 questions on motion & graphs, forces & equilibrium, energy, work & power, momentum & collisions, pressure & fluids, waves & sound and electricity & circuits. Answer what you can, then check your answers to see which topics are secure and what to practise next.

14 questions7 topicsAbout 15 minutesSet 4 of 5

Skip a question if you do not know the answer. It is better than guessing, because it shows what to practise.

1Motion & graphsA rover travels 82 m in 59 s, then 85 m in 45 s. Find its average speed for both stages. Round to 3 decimal places if needed. Answer in m/s.
m/s
2Motion & graphsVelocity is a constant −3 m/s for 5 s. Find displacement.
m
3Forces & equilibriumOn a weightless balanced beam, 87 N acts 4 m left of the pivot. What downward force at 10 m right balances it? Forces are perpendicular to the beam. Round to 3 decimal places if needed. Answer in N.
N
4Forces & equilibriumA 2 kg cart has horizontal forces 119 N right and 98 N left. No other horizontal forces act. Taking right as positive, find its acceleration. Round to 3 decimal places if needed. Answer in m/s².
m/s²
5Energy, work & powerA 3 kg load is raised vertically by 21 m in a field g = 10 N/kg. Find its gravitational potential-energy gain. Round to 3 decimal places if needed. Answer in J.
J
6Energy, work & powerA device receives 210 J and has useful-energy efficiency 20%. Find the useful output energy. Round to 3 decimal places if needed. Answer in J.
J
7Momentum & collisionsA 20 kg object has signed velocity -9 m/s on a chosen axis. Find its signed momentum. Round to 3 decimal places if needed. Answer in kg·m/s.
kg·m/s
8Momentum & collisionsA 9 kg object changes signed velocity from -17 m/s to 11 m/s. Find the net impulse on it. Round to 3 decimal places if needed. Answer in N·s.
N·s
9Pressure & fluidsAn object displaces 40 litres of fluid of density 1100 kg/m³. Use g = 10 N/kg and 1 litre = 0.001 m³. Find buoyant force. Round to 3 decimal places if needed. Answer in N.
N
10Pressure & fluidsA normal force of 37 N acts uniformly over 0.83 m². Find the pressure. Round to 3 decimal places if needed. Answer in Pa.
Pa
11Waves & sound12 complete oscillations take 22 s. Find the period. Round to 3 decimal places if needed. Answer in s.
s
12Waves & soundA wave has frequency 108 Hz and wavelength 3.3 m. Find its speed. Round to 3 decimal places if needed. Answer in m/s.
m/s
13Electricity & circuitsA battery supplies 3.4 A to two parallel branches. One branch carries 0.2 A. What current flows in the other branch? (Assume ideal wires and an ideal battery.)
A
14Electricity & circuitsA model device uses constant power 1875 W for 19 h. Find the energy in kilowatt-hours. Round to 3 decimal places if needed. Answer in kWh.
kWh