Answer:
Power, P = 722.96 watts
Explanation:
It is given that,
Voltage, V = 120 V
Length of nichrome wire, l = 8.9 m
Diameter of wire, d = 0.86 mm
Radius of wire, r = 0.43 mm = 0.00043 m
Resistivity of wire, 
We need to find the power drawn by this heater. Power is given by :

And, 


P = 722.96 watts
So, the power drawn by this heater element is 722.96 watts. Hence, this is the required solution.
Answer: The square root of Pi is 1.77245.
Please mark as brainliest
Answer:
0.125 volts
Explanation:
The induced emf can be sufficient to stimulate neuronal activity.
One such device generates a magnetic field within the brain that rises from zero to 1.5 T in 120 ms.
We need to find the induced emf within a circle of tissue of radius 1.6 mm and that is perpendicular to the direction of the field. The formula for the induced emf is given by :

Where
is magnetic flux
So,

So, the induced emf is equal to 0.125 volts.
Answer:
The wave speed is calculated below:
Explanation:
Given,
number of waves passed per minute = 8
time period = 1 minute = 60 s
distance between successive wave crests = 20 m
waves passing interval per second =

Now,
wave speed = 20 m ×

=
m/s
= 2.67 m/s
Hence the wave speed is 2.67 m/s.