IGCSE Physics (2024) Year 10
Chapter 1:
Making
Measurements
© James Gan 1
IGCSE Physics (2024) Year 10
1.1 Measuring Length
1. In the laboratory, lengths are often measured using a ruler.
2. It is
important to think
critically about the
measurements you
make, however
straightforward they
seem
Example 1:
a piece of
to be.
Measuring the length of
wire
Precautions:
1. The wire must be straight.
2. The wire must line up against the 0 on the scale.
3. The ruler used must be
properly calibrated.
Example 2: Measuring the
thickness of a sheet of paper
Method:
1. Take a stack of 500 sheets and measure its thickness with a ruler.
2. Then, divide by 500 to take the thickness of one sheet.
Example 3: Measuring curved line
Method:
1. Lay a thread on the line.
2. Mark the thread at either end of the line and then lay it along a ruler to find the
length.
SI Unit for Length
1. Metre (m)
1 decimetre (dm)
= 0.1m
1 centimetre (cm)
= 0.01m
1 millimetre (mm)
= 0.001m
1 micrometre (μm)
= 0.000001m
1 kilometre (km)
= 1000m
© James Gan 2
IGCSE Physics (2024) Year 10
Past Year Question
© James
Gan 3
IGCSE Physics (2024) Year 10
1.2 Measuring Volumes
A.
Measuring the volume of regular shapes
• Often, we just need to take one or two
measurements of the shape property (radius, height) and look up the
equation for volume.
B. Measuring the volume of irregular shapes
• The technique used to measure irregular shapes is called displacement.
Steps:
1. Select a measuring cylinder that is larger than the object.
2.
Partially fill it with water.
Note
the volume of the water.
3.
Immerse the object in the
water.
4. The
increase in volume is equal
to the
volume of the object.
C. Measuring the volume of liquid
• Measuring cylinder is used.
• Note: Use a small size measuring cylinder to measure small volume.
SI Unit for Volume
1. Cubic Metre (m3)
1 cubic centimetre (cm3)
= 0.000001 m3
1 cubic decimetre (dm3)
= 0.001 m3
© James Gan 4
IGCSE Physics (2024) Year 10 1.3 Measuring Time
1. In the laboratory, you might need to record the temperature of a container of
water every minute or find out how long an electric current is flowing. 2. There
are 2 types of timing device:
a. Analogue clock
b. Digital clock
Analogue clock
• It can be used to measure time intervals to no better than the nearest second
Digital clock
• Example: Stopwatch
Introducing the lab pendulum
1. The time for one oscillation of a pendulum (moving from left to right) is called its
period.
2. As a pendulum swings at a steady rate, you can use a stopwatch to measure the
time for a large number of oscillations and calculate the average time per
oscillation.
3. Any inaccuracy in the time at which the stopwatch is started and stopped will be
much less significant if you measure the total time for a large number of
oscillations.
© James Gan 5
IGCSE
Physics
(2024)
Year 10
Past
Year
Question
A student is trying to see how quickly they can run 5.0 km on a standard 400 m running
track. They reason that, if they know how fast they can run one lap, they can assume they
will run at the same speed for 5.0 km, and can calculate their predicted time.
They, correctly, reason that they will not be able to maintain their initial pace
throughout the whole 5.0 km, so they decide to time lap 5.
The diagram shows the reading on the stopwatch at the beginning and the end of lap 5.
© James Gan 6
IGCSE Physics (2024) Year 10
1.4 Measuring Density
1. The mass of an object is the quantity of matter it is made of.
2. The density tells us how concentrated an object’s mass is.
Illustration:
Dense Object
Less Dense Object
Formula of density:
Symbol for density:
Units of density:
Unit of mass
Unit of volume
Unit of density
Density of water
Density implication:
1. If an object is denser than water, then it will sink.
2. If an object is less dense than water, then it will float.
Worked Example 1:
A sample of ethanol has a volume of 240 cm3. Its mass is found to be 190.0g. What is the
density of ethanol?
© James Gan 7
IGCSE Physics (2024) Year 10
Worked Example 2:
A box full of 35 matches has a mass of 6.77g. The box itself has a mass of 3.37g. a. What is
the mass of one match in grams?
b. What is the volume (in cm3) of each match. A match has a dimension of 42mm x 2.3mm x
2.3mm? (Tips: Convert mm to cm first before doing any calculation)
c. What is the density of the matches?
d. How do you know if these matches will float?
Finding the density of liquid
1. Place a measuring cylinder on a balance.
2. Set the balance to zero.
3. Pour liquid into the cylinder.
4. Read the volume from the scale on the cylinder. Read the balance reading for mass. 5.
Calculate the density of the liquid using the density formula.
© James Gan 8
IGCSE Physics (2024) Year 10
Past Year Questions
2.
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