Efficiency = useful energy out / total energy in x 100
= 100/400 x 100
=0.25 x 100
= 25%
25%
Answer:
P = 2439.5 W = 2.439 KW
Explanation:
First, we will find the mass of the water:
Mass = (Density)(Volume)
Mass = m = (1 kg/L)(10 L)
m = 10 kg
Now, we will find the energy required to heat the water between given temperature limits:
E = mCΔT
where,
E = energy = ?
C = specific heat capacity of water = 4182 J/kg.°C
ΔT = change in temperature = 95°C - 25°C = 70°C
Therefore,
E = (10 kg)(4182 J/kg.°C)(70°C)
E = 2.927 x 10⁶ J
Now, the power required will be:

where,
t = time = (20 min)(60 s/1 min) = 1200 s
Therefore,

<u>P = 2439.5 W = 2.439 KW</u>
Answer:
vf = 0
Explanation:
Since the initial height hi = 0, we can rewrite the energy equation as
vf^2 = vi^2 - 2ghf = (10 m/s)^2 - 2(10 m/s^2)(5 m) = 0
Therefore, his final velocity vf is
vf = 0
Answer:
The final graph
Explanation:
The graph that curves downwards is negative acceleration. While the position decreases the slop increases.
Answer:
The planet Jupiter completes one revolution of the sun in 362710000 seconds. Long time, right?
Explanation:
3.154x10^7=3.154x10000000=31540000
11.5x31540000=362710000