Examstyle Questions: Units, Quantities and Measurements

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)

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)

The acceleration, a, of a body in simple harmonic motion is given by:
a =  (2πf)^{2}x
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)