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Q1.
A teacher demonstrated how a magnetic field can cause a copper rod to accelerate.
The teacher placed the copper rod on two brass rails in a magnetic field.
The copper rod was able to move.
The teacher closed the switch and the copper rod accelerated uniformly from rest for
0.15 s.
The current in the copper rod was 1.7 A.
mass of copper rod = 4.0 g
length of copper rod in the magnetic field = 0.050 m
magnetic flux density = 0.30 T
Calculate the maximum possible velocity of the copper rod when it left the magnetic field.
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Maximum velocity = _______________ m/s
(6)
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F = B × I × L
F = 0.30 × 1.7 × 0.050 = 0.0255 N
F = m × a
Given mass m = 0.0040 kg
So:
0.0255 = 0.0040 × a
a = 0.0255 ÷ 0.0040 = 6.375 m/s²
a = Δv ÷ tΔv = a × t
Δv = 6.375 × 0.15 = 0.95625 m/sFinal answer: Δv = 0.96 m/s

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