PHYSICS - Physical Quantities & Units

A plumber needs to measure the internal diameter of a water tap as accurately as possible.

Which instrument should be used?

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What is the length of the feather?

• 19 mm

• 29 mm

• 19 cm

• 29 cm

A student wishes to find the volume of a small, irregularly-shaped stone.

A ruler and a measuring cylinder containing some water are available. Which apparatus is needed?

• neither the ruler nor the measuring cylinder

• the measuring cylinder only

• the ruler and the measuring cylinder

• the ruler only

Which quantity is this instrument used to measure?

• area

• density

• mass

• volume

Which option contains only apparatus that could be used to determine the volume of a small block of unknown material?

• measuring cylinder, metre rule

• measuring cylinder, stopwatch

• metre rule, balance

• metre rule, stopwatch

The diameter of a copper wire is thought to be approximately 0.3mm. Which instrument should be used to obtain a more accurate measurement of the diameter of the wire?

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Which measurement can be made using a micrometer screw gauge?

• the air pressure of a tyre

• the diameter of a wire

• the turning effect of a spanner

• the wavelength of microwaves

Which set of quantities are all vectors?

Vector: Has magnitude (value) and direction

• acceleration, displacement, velocity

• chemical energy, mass, power

• extension, force, gravitational potential energy

• weight, kinetic energy, work

Which quantity is a vector?

• energy

• force

• speed

• time

Newton’s third law involves two quantities which are equal in size and opposite in direction.

What is the unit for these two quantities?

This is Force (vector quantity)

• J

• m / s²

• N

• W