A woman can row her canoe at 2.5 m/s. If she faces an opposing current of 3.0 m/s, how fast will she go forward?
1 answer:
Answer:
V = - 0.5 [m/s]
Explanation:
In order to solve this problem, we must use the principle of relative speeds. This is for an observer who is on the edge of the river he can see how the river moves to the left and the woman tries to move to the right but can not since:
That is, the person sees how the woman moves to the left but with avelocity of 0.5 [m/s] to the left
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Answer:
a) 1.34*10^-8 W
b) 1.18*10^-5 H
c) 20mV
Explanation:
a) To find the average magnetic flux trough the inner solenoid you the following formula:
mu_o: magnetic permeability of vacuum = 4pi*10^-7 T/A
N: turns of the solenoid = 340
I: current of the inner solenoid = 0.100A
A: area of the inner solenoid = pi*r^2
r: radius of the inner solenoid = 2.00cm/2=1.00cm=10^-2m
You calculate the area and then replace the values of N, I, mu_o and A to find the magnetic flux:
the magnetic flux is 1.34*10^{-8}W
b) the mutual inductance is given by:
N1: turns of the outer solenoid = 22
N2: turns of the inner solenoid
A_2: area of the inner solenoid
l: length of the solenoids = 25.0cm=0.25m
by replacing all these values you obtain:
the mutual inductance is 1.18*10^{-5}H
c) the emf induced can be computed by using the mutual inductance and the change in the current of the inner solenoid:
by replacing you obtain:
the emf is 20mV