Exam-style Questions: Units, Quantities and Measurements
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Here is a list of five units for physical quantites.
kgm-3
Nm-2
Cs-1
Ω m
Ws
From the list
a) write down the unit for electrical current ................
b) write down the unit for mechanical stress ................
(2 Marks)
(Marks available: 2)
Answer outline and marking scheme for question: 1
a) Cs-1
b) N m-2
(2 Marks)
(Marks available: 2)
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Here is a list of five units
J
N
Jkg-2
Nkg-1
From the list write down the correct unit for
a) the energy stored in a stretched spring ................
b) centripetal force ................
(Marks available: 2)
Answer outline and marking scheme for question: 2
a) the energy stored in a stretched spring .............J...
b) centripetal force .........N.......
(Marks available: 2)
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The acceleration, a, of a body in simple harmonic motion is given by:
a = - (2πf)2x
Where f if frequency of the oscillation and x is the displacement.
Show that the right hand side of the equation has the units of acceleration.
(Marks available: 2)
Answer outline and marking scheme for question: 3
Unit of f 2 is s-2 (1 Mark) or f is s-1 (unit of x is m therefore)
combined unit is m s-2 (which is the uni of acceleration) (1 Marks)
(Marks available: 2 Marks)