Refraction occurs when a wave enters a new medium and changes its speed.
i hope this helps
I’m sure it’s called a circuit:)
Answer:
R2 = 10.31Ω
Explanation:
For two resistors in parallel you have that the equivalent resistance is:
(1)
R1 = 13 Ω
R2 = ?
The equivalent resistance of the circuit can also be calculated by using the Ohm's law:
(2)
V: emf source voltage = 23 V
I: current = 4 A
You calculate the Req by using the equation (2):

Now, you can calculate the unknown resistor R2 by using the equation (1):

hence, the resistance of the unknown resistor is 10.31Ω
Answer:
22.505 seconds
Explanation:
V =19.8m/s
V = a*to
t1 = 19.8/3.3
= 6seconds
Distance travelled during acceleration
= 1/2 x 3.3 x 6²
= 59.4m
X_total = x1 + x2
X2 = 373-59.4
X2 = 313.6m
t2 = x2/v
= 313.6/19.8
= 16.505
Total = 16.505 + 6
= 22.505 seconds
the minimum time in which an elevator can travel the 373 m from the ground floor is 22.505 seconds.
Answer:
(a) 
(b) 
Explanation:
(a) The surface current density of a conductor is the current flowing per unit length of the conductor.

Considering a wire, the current is uniformly distributed over the circumferenece of the wire.

The radius of the wire = a

The surface current density 
(b) The current density is inversely proportional
......(1)
k is the constant of proportionality

........(2)
substituting (1) into (2)





substitute 
