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2. Moving fast: speed
Cheetahs can reach a top speed of
120 km/h, while gazelles can only In Unit 1 you learnt:
reach 80 km/h. Yet a cheetah fails to ✔ what physical quantities are
catch a gazelle 6 times out of 10! Why ✔ the difference between scalar and vector Physics
textbooks nis edu kz
do you think the cheetah is sometimes quantities
unable to catch the gazelle despite
✔ how to measure length and time, considering
the fact that its top speed is higher? measurement errors in scientific instruments
In Unit 2 you will learn:
✔ what distance, displacement and speed are
✔ how to explain uniform motion
✔ the concepts of trajectory and relative motion
✔ distance vs. time graphs and speed vs. time
graphs for different situations
Key phrases:
✔ Speed of object is calculated according to the
equation … and measured in …
✔ Distance has only … , while displacement has …
and …
✔ An object moves uniformly when …
✔ It is important to know the direction of speed of
an object because …
CCL In Maths classes you have learned how
to record large and small numbers in standard
form. These skills will help you in problem-solving
in Physics. You have also learned how to plot
and explain graphs. These skills will help you in
studying speed and uniform motion.
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