Answer:
hellooooo :) ur ans is 33.5 m/s
At time t, the displacement is h/2:
Δy = v₀ t + ½ at²
h/2 = 0 + ½ gt²
h = gt²
At time t+1, the displacement is h.
Δy = v₀ t + ½ at²
h = 0 + ½ g (t + 1)²
h = ½ g (t + 1)²
Set equal and solve for t:
gt² = ½ g (t + 1)²
2t² = (t + 1)²
2t² = t² + 2t + 1
t² − 2t = 1
t² − 2t + 1 = 2
(t − 1)² = 2
t − 1 = ±√2
t = 1 ± √2
Since t > 0, t = 1 + √2. So t+1 = 2 + √2.
At that time, the speed is:
v = at + v₀
v = g (2 + √2) + 0
v = g (2 + √2)
If g = 9.8 m/s², v = 33.5 m/s.
A standard 60 W light bulb has a voltage of 130 volts. So, we use this conversion, the Faraday's constant which is equal to approximately 96,500 Coulombs per mole electron, and the Avogadro's number equal to 6.022×10²³ particles/mole . The solution is as follows:
W = Energy/time
60 W = x J/1 s
x = 60 J = 60 C·V
(60 C·V)*(1/130 V)*(1 mole e/96,500 C)*(6.022×10²³ electrons/mole electron)
= 2.88×10¹⁸ electrons
Change in temperature = final temperature - Initial temperature
Δt = t₂ - t₁
Δt = 17 - (-6)
Δt = 17 + 6 = 23 f
In short, Your Answer would be Option D
Hope this helps!
