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Grade 8 · Physics

Grade 8 Physics diagnostic

12 questions on motion & graphs, forces & equilibrium, energy, work & power, 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.

12 questions6 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 358 m in 38 s, then 194 m in 16 s. Find its average speed for both stages. Round to 3 decimal places if needed. Answer in m/s.
m/s
2Motion & graphsOn an east-positive axis, position changes from -43 m to 21 m in 21 s. Find the signed average velocity. Round to 3 decimal places if needed. Answer in m/s.
m/s
3Forces & equilibriumOn a weightless balanced beam, 45 N acts 5 m left of the pivot. What downward force at 4 m right balances it? Forces are perpendicular to the beam. Round to 3 decimal places if needed. Answer in N.
N
4Forces & equilibriumA 10 kg cart has horizontal forces 37 N right and 29 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 device receives 930 J and has useful-energy efficiency 5%. Find the useful output energy. Round to 3 decimal places if needed. Answer in J.
J
6Energy, work & powerA model device transfers energy at constant power 175 W for 53 s. Find the transferred energy. Round to 3 decimal places if needed. Answer in J.
J
7Pressure & fluidsA normal force of 292 N acts uniformly over 0.36 m². Find the pressure. Round to 3 decimal places if needed. Answer in Pa.
Pa
8Pressure & fluidsAt the same normal force, halving area does what to pressure?
9Waves & soundA wave has frequency 46 Hz and wavelength 3.7 m. Find its speed. Round to 3 decimal places if needed. Answer in m/s.
m/s
10Waves & sound37 complete oscillations take 14 s. Find the period. Round to 3 decimal places if needed. Answer in s.
s
11Electricity & circuitsAn ohmic resistor of 45 Ω has potential difference 12 V. Find current. This is a paper calculation, not a construction instruction. Round to 3 decimal places if needed. Answer in A.
A
12Electricity & circuitsA constant current of 3.5 A flows for 32 s. Find transferred charge. Round to 3 decimal places if needed. Answer in C.
C