Question 15
Complete Fig 1.1 to show each
quantity and its unit. [4]
Quantity Unit
speed m s-1
density
s-1
electric
field strength
kg
m s-1
Reference: Past Exam Paper – June 2003 Paper 2 Q1
Solution:
Quantity Unit
speed m s-1
density kg m-3
frequency s-1
electric field strength N
C-1 or V m-1 or kg m s-2 C-1
momentum or impulse kg m s-1
{The unit of density is kg
m-3 (= mass / volume).
A unit of s-1
means that the quantity is ‘something divided by time’. The numerator should
not have any unit. This could be frequency (= 1 / period) or count rate or
activity or decay constant.
The question has NOT asked
for the SI BASE unit. So, the unit of electric field strength can be given as N
C-1 (= force / charge) or V m-1 (= p.d. / distance) or in
SI base units, kg m2 C-1. However, there was no need to
convert into SI base unit as this was not specified in the question.
In the unit kg m s-1,
kg is the unit of mass and m s-1 is the unit of velocity. The
quantity represented by ‘mass × velocity’ is momentum (or impulse).}
No comments:
Post a Comment
If it's a past exam question, do not include links to the paper. Only the reference.
Comments will only be published after moderation