Let her initial velocity be U.
Let the width of the river be W.
She swims 3/5 the width of the river at U.
Remainder width = (1 - 3/5) = 2/5.
She then swims 2/5 the width with velocity U/2.
Average Speed = (Total Distance Traveled) / ( Total Time Taken).
Distance = Speed * time
time = Distance / Speed.
Time in first trip: = (3/5)W / U = 0.6W/U.
Time in second trip = (2/5)W / (U/2) = 0.4W / 0.5 U = 0.8W/U
Total Distance Traveled = W, width of the river.
Average Speed = W / (0.6W/U + 0.8W/U) = W / (1.4W/U)
= W * U / 1.4W
= U/1.4
= U * 10 / 14
= (5/7) U.
Therefore Average speed is (5/7) of the initial speed.
The circuit is in parallel connection
Equivalent resistance = 1/Req = 1/R1 + 1/R2 + 1/R3
From the information given,
R1 = 5
R2 = 2
R3 = 4
1/Req = 1/5 + 1/2 + 1/4 = (4 + 10 + 5)/20 = 19/20
Req = 20/19 = 1.053 ohms
I = V/R
Given that V = 12,
Current flow through circuit = 12/1.053 = 11.4 A
I1 + I2 + I3 = 11.4
I1 = 12/5 = 2.4 A
I2 = 12/2 = 6 A
I3 = 12/4 = 3A
This is because AC is easier to transform from a higher voltage to another, lower voltage, using transformers. High voltage means less <span>resistive losses in the power lines during transmission. This is why power is transmitted at many hundreds of thousands of volts and is only transformed into 110V or 220V near the consumers. </span>
If the coefficient alpha for a stress scale was computed to be 0.80, the scale would be strongly reliable. A coefficient alpha that is at least 0.70 and above is considered to have a strong internal consistency, which means the items in the scale are closely related as a group.
