<span>The correct option is D) both A and B. In fact, the strength of an electric field produced by a single point charge is given by
</span>
<span>
where Q is the charge that generates the field, k is the Coulomb's constante and r is the distance from the charge source of the field.
From the equation, we see that the strength of the field depends on A) the amount of charge that produced the field (Q) and B) the distance from the charge (r), so the correct option is D.</span>
Answer
given,
time = 10 s
ship's speed = 5 Km/h
F = m a
a is the acceleration and m is mass.
In the first case
F₁=m x a₁
where a₁ = difference in velocity / time
F₁ is constant acceleration is also a constant.
Δv₁ = 5 x 0.278
Δv₁ = 1.39 m/s
a₁ = 0.139 m/s²
F₂ =m x a₂
F₃ = F₂ + F₁
Δv₃ = 19 x 0.278
Δv₃ = 5.282 m/s
a₃=Δv₂ / t
a₃ = 0.5282 m²/s
m a₃=m a₁ + m a₂
a₃ = a₂ + a₁
0.5282 = a₂ + 0.139
a₂=0.3892 m²/s
F₂ = m x 0.3892...........(1)
F₁ = m x 0.139...............(2)
F₂/F₁
ratio = 
ratio = 2.8
calculate the power per hour of a radiator, knowing that it is connected to a common 110 v contact. and requires 20 Amp.
Answer:
2.2kWh
Explanation:
Given parameters:
Potential difference = 110v
Current = 20A
Unknown:
Power = ?
Solution:
To solve this problem, we use the expression below:
Power = IV
Power = 110 x 20 = 2200W
This is therefore 2.2kW
Power per hour = 2.2kWh
It really depends on what the bulb is being used for, since efficiency means how much of the output is USEFUL.
If the bulb is being used for light in a dark room, then it produces (8.2% x 21W) = 1.72 joules per second of light energy.
If the bulb is being used to keep a hamster cage or a fish tank warm, then the 8.2% is the useful part, and the light is the other (91.8% x 21W) = 19.28 joules per second.
