Complete Question:
Find the resistance of a wire of length 0.65 m, radius 0.25 mm and resistivity 3 * 10^{-6} ohm-metre.
Answer:
Resistance = 9.95 Ohms
Explanation:
<u>Given the following data;</u>
Length = 0.65 m
Radius = 0.25 mm to meters = 0.00025 m
Resistivity = 3 * 10^{-6} ohm-metre.
To find the resistance of the wire;
Mathematically, resistance is given by the formula;

Where;
- P is the resistivity of the material.
- L is the length of the material.
- A is the cross-sectional area of the material.
First of all, we would find the cross-sectional area of the wire.
Area of circle = πr²
Substituting into the equation, we have;
Area = 3.142 * (0.00025)²
Area = 3.142 * 6.25 * 10^{-8}
Area = 1.96 * 10^{-7} m²
Now, to find the resistance of the wire;


<em>Resistance = 9.95 Ohms </em>
Answer:
<em>155.80rad/s</em>
Explanation:
Using the equation of motion to find the angular acceleration:

is the final angular velocity in rad/s
is the initial angular velocity in rad/s
is the angular acceleration
t is the time taken
Given the following

Time = 4.1secs
Convert the angular velocity to rad/s
1rpm = 0.10472rad/s
6100rpm = x
x = 6100 * 0.10472
x = 638.792rad/s
Get the angular acceleration:
Recall that:

638.792 = 0 + ∝(4.1)
4.1∝ = 638.792
∝ = 638.792/4.1
∝ = 155.80rad/s
<em>Hence the angular acceleration as the blades slow down is 155.80rad/s</em>
Research has shown that the electrons orbit the nucleus in circular motions as shown on the classic Bohr model. FALSE
The equation of our ellipse is:
(1)
First, let's reduce the equation of the ellipse to the standard form:

To do that, we should divide both terms of equation (1) by 6400, and we get:

This is a vertical ellipse (because
) centered in the origin, and so the distance of its foci from the origin (on the y axis) is given by

Therefore, the position of the two foci is (0,6) and (0,-6)