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State the SI unit of mass.
kilogram (kg)
Which of the following is a scalar quantity: velocity, force, distance, displacement?
distance
A student measures a time interval of 2.5 minutes. Express this in seconds.
150 s
Name one instrument used to measure length accurately.
Vernier caliper / micrometer screw gauge
Define vector quantity. Give one example.
A physical quantity that has both magnitude and direction, e.g. velocity / displacement / force
State the formula for density.
density = mass ÷ volume
A block has mass 200 g and volume 50 cm³. Find its density in g/cm³.
200 ÷ 50 = 4 g/cm³
Convert your answer in Q7 to SI unit (kg/m³).
4000 kg/m³
How do you determine the volume of an irregular solid object?
Use displacement method (measure volume of water displaced in measuring cylinder).
Why does a wooden block float on water while a metal block sinks?
Because density of wood < density of water, while density of metal > density of water.
Define speed.
Distance travelled per unit time.
A car travels 100 m in 20 s. Calculate its average speed.
100 ÷ 20 = 5 m/s
State the difference between speed and velocity.
Speed is scalar (no direction), velocity is vector (includes direction).
Define acceleration.
Rate of change of velocity per unit time.
A ball increases its velocity from 4 m/s to 10 m/s in 3 s. Find acceleration.
(10 – 4) ÷ 3 = 2 m/s²
From a velocity-time graph, what does the slope represent?
Acceleration
