Answer:
2.828 km
Explanation:
radius of lake, r = 2 km
Let O be the centre of the circular lake and you walk from A to A to D.
Displacement is the measure of shortest distance between two points.
According to the diagram , the displacement AD is
(By using the Pythagorean theorem)

AD = 2.828 km
thus, the displacement is 2.828 km.
Answer:
1341.03 V/m
Explanation:
The power output per unit area is the intensity and also the is the magnitude of the Poynting vector.
= cε₀
⇒
= cε₀
Where;
P is the power output
A is the area of the beam
c is speed of light
ε₀ is permittivity of free space 8.85 × 10⁻¹² F/m
is the average (rms) value of electric field
Making electricfield
the subject of the equation
= P / Acε₀
= √(P / Acε₀)
But area A = πr²
= √(P / πr²cε₀)
Given:
Output power, P = 15 mW = 0. 015 W
Diameter, d = 2 mm = 0.002 m
⇒ Radius,
Solving for average (rms) value of electric field;
= 1341.03 V/m
Answer:
When we talk about residential uses of energy, these are the most basic uses of energy . They include watching television, washing clothes, heating and lighting at home , taking a shower, working from home on your laptop or computer, running appliances and cooking.
Answer: 15m/s
Explanation: <u>Average</u> <u>Velocity</u> is vector describing the total displacement of an object and the time taken to change its position. It is represented as:

At t₁ = 1.0s, displacement x₁ is:

x(1) = 28
At t₂ = 4.0s:

x(4) = 73
Then, average speed is

v = 15
The average velocity of a car between t₁ = 1s and t₂ = 4s is 15m/s