Efficiency = (useful output) / (input)
Efficiency = (35 J) / (125 J) = 0.28 = 28%
Answer:
v_f = 24.3 m / s
Explanation:
A) In this exercise there is no friction so energy is conserved.
Starting point. On the roof of the building
Em₀ = K + U = ½ m v₀² + m g y₀
Final point. On the floor
Em_f = K = ½ m v_f²
Emo = Em_g
½ m v₀² + m g y₀ = ½ m v_f²
v_f² = v₀² + 2 g y₀
let's calculate
v_f = √(10² + 2 9.8 25)
v_f = 24.3 m / s
It transfers the electrical current from the point of contact on the lightning rod into the ground.
Light can be seen as an electromagnetic wave.
What happens when two waves, with the same frequency, superpose is called interference.
If at a certain point two waves arrive both with a crest, we have constructive interference and the amplitudes sum up, reaching the maximum value, resulting in bright spots.
If at a certain point one of the waves arrives with a crest and the other wave arrives with a trough, we have destructive interference, and the two amplitudes cancel out, resulting in dark spots.
Therefore, t<span>he dark bands on the wall are from destructive interference.</span>
