Q26 · 2024 · Paper 1Simple familiar3 marks
QUESTION 26 (3 marks)
The centres of two small equally positively charged metallic spheres are separated by a distance of 0.30 m and experience a force of 0.025 N between them. Calculate the charge on each of the metallic spheres. Show your working.
WORKED SOLUTION
3 marksQCAA guide · typeset solution
ANSWER
See worked solution below.
Worked solution
2
0
1
4
Qq
F
r
π
=
9
2
9
7
2
2
0.0
0
25 0
0
.3
0
9
0.3
1
0
9
1
. 2
0
10
5
5
.0
0
Q
Q
−
×
×
=
×
=
×
×
=
Charge =
7C
1
5 0
0
.
−
×
• recognises the scenario relates to
Coulomb’s Law [1 mark]
• recognises the charges have the same
value in the equation [1 mark]
• calculates the charge of the metallic
spheres to be
7C
1
5 0
0
.
−
×
[1 mark]
One QCAA sample method typeset for web; criterion wording is adapted from the official marking guide.
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