Answer:
The power decreases by 36%
Explanation:
Given:
At 20° C
Power, P₀ = 300 W
Potential difference, V = 150 volts
Now, power is given as
P = V²/R
where, R is the resistance
on substituting the values, we get
300 = 150²/R₀
or
R₀ = 75 Ω
Now, the variation of resistance with temperature is given as
R = R₀[1 + α(T - T₀)]
where, α is the temperature coefficient of resistivity = 0.0003125 (°C⁻¹)
now, at
T₀ = 20° C
R₀ = 75 Ω
for
T = 1820° C
we have
R = R₀[1 + α(T - T₀)]
substituting the values
we get
R = 75×[1 + 0.0003125 × (1820 - 20)]
or
R = 117.18 Ω
Now using the formula for power
We have,
P = V²/R
or
P = 150²/117.18 = 192 W
Therefore, the percentage change will be
= 
on substituting the values , we get
= 
= -36%
here, negative sign depicts the decrease in power
Answer:
i am pretty sure you are correct and so sorry if i am wrong i am just trying to help no need to give me anything if i am right but it might be the one abouve the one you chose :) please let me know if i am wrong or right
Explanation:
<span>The correct answer is B. Inverted image. This is because of all the lenses and light refractions and what not. The same things happens with our eyes except our brains fix the inverted image automatically. Since there are no brains in a projector, you have to fix it on your own by putting it in reverse.</span>
Answer:
There must be an equal amount of each element on both sides of the equation. Hope this helps and please marks as the brainliest.
Explanation:
Answer:
Explanation:
<u>Simple Pendulum</u>
It's a simple device constructed with a mass (bob) tied to the end of an inextensible rope of length L and let swing back and forth at small angles. The movement is referred to as Simple Harmonic Motion (SHM).
(a) The angular frequency of the motion is computed as
We have the length of the pendulum is L=0.81 meters, then we have
(b) The total mechanical energy is computed as the sum of the kinetic energy K and the potential energy U. At its highest point, the kinetic energy is zero, so the mechanical energy is pure potential energy, which is computed as
where h is measured to the reference level (the lowest point). Please check the figure below, to see the desired height is denoted as Y. We know that
And
Solving for Y
The potential energy is
The mechanical energy is, then
(c) The maximum speed is achieved when it passes through the lowest point (the reference for h=0), so the mechanical energy becomes all kinetic energy (K). We know
Equating to the mechanical energy of the system (M)
Solving for v
