D.On the ocean floor. When tectonic plates move, They move along the ocean floor, which is the crust, and It causes earthquakes and volcanoes and also caused Pangea to break apart and become what it is now The seven continents.
Answer:
a) L = 3.29 10⁻⁴ H, b)U = 5.33 10⁻² J
Explanation:
a) The inductance is a solenoid this given carrier
L =
The magnetic field inside the solenoid is
B = μ₀
hence the magnetic flux
Ф_B = B. A = μ₀
we substitute in the expression of inductance
L = N² μ₀ A /l
let's find the area of each turn
A = π r²
A = π 0.02²
A = 1.2566 10⁻³ m²
let's calculate
L = 250² 4π 10⁻⁷ 1.2566 10⁻² / 0.3
L = 3.29 10⁻⁴ H
b) The stored energy is
U = ½ L i²
let's calculate
U = ½ 3.29 10⁻⁴ 18²
U = 5.33 10⁻² J
Answer:
<em>The average speed of the train is 45 km/h</em>
Explanation:
<u>Speed</u>
It's defined as the distance (d) per unit of time (t) traveled by an object. The formula is:

Let's call x the total distance covered by the train. It covered d1=1/3x with a speed of v1=25 km/h. The time taken is calculated solving for t:



Now the rest of the distance:
d2 = x - 1/3x = 2/3x
Was covered at v2=75 km/h. Thus the time taken is:



The total time is:



Simplifying:

The average speed is the total distance divided by the total time:

Simplifying:

The average speed of the train is 45 km/h