That n2 = 2*n1. That is, the index of refraction is twice as big in medium 2 since v=c/n
Answer:
2.25m/s
Explanation:
wavelength=4.5m
period=2sec
frequency= 1/period
=1/2
speed= wavelength×wave frequency
=4.5×1/2
=2.25 m/s
so, none of the options are correct
A motor spins upward the flywheel with a persistent torque
of 50N⋅m.
What time does it take the flywheel to get to the top speed?
From the equation:
Tj = J*dω/dt
you can get the two equations:
Δt1= J1*Δω/Tj = 240*125.66/50 = 603.17 sec
Δt2= J2*Δω/Tj = 120*125.66/50 = 301.58 sec
Transformer contains two coils: primary and secondary. They allow change of voltage to lower or higher value. In first case we have step-down and in second case we have step-up transformer.
Formula used for transformer is:

Where:N1 = number of turns on primary coilN2 = number of turns on secondary coilV1 = voltage on primary coilV2 = voltage on secondary coil
In a step-down transformer primary coil has more turns than secondary coil. So the ratio 1:38 means that for each turn on secondary coil we have 38 turns on primary coil.
We can solve the equation for V2:

Secondary coil provides voltage of 3.16V.