Since it was stated that it must move at constant
velocity, so the only force it must overpower is the frictional force.
So the equation is:
F cos θ = Ff
F cos 36 = 65 N
F = 80.34 N
<span>So the nurse must exert 80.34 N of force</span>
Answer:
The needed energy to melt of ice is 1670 J.
Explanation:
Given that,
Mass of ice = 5 g
Specific latent heat = 334000 J/kg
We need to calculate the energy
Using formula of energy

Where, m = mass
L = latent heat
Put the value into the formula


Hence, The needed energy to melt of ice is 1670 J.
(6) Wagon B is at rest so it has no momentum at the start. If <em>v</em> is the velocity of the wagons locked together, then
(140 kg) (15 m/s) = (140 kg + 200 kg) <em>v</em>
==> <em>v</em> ≈ 6.2 m/s
(7) False. If you double the time it takes to perform the same amount of work, then you <u>halve</u> the power output:
<em>E</em> <em>/</em> (2<em>t </em>) = 1/2 × <em>E/t</em> = 1/2 <em>P</em>
<em />
When the capacitor is connected to the voltage, a charge Q is stored on its plates. Calling
the capacitance of the capacitor in air, the charge Q, the capacitance
and the voltage (
) are related by
(1)
when the source is disconnected the charge Q remains on the capacitor.
When the space between the plates is filled with mica, the capacitance of the capacitor increases by a factor 5.4 (the permittivity of the mica compared to that of the air):

this is the new capacitance. Since the charge Q on the plates remains the same, by using eq. (1) we can find the new voltage across the capacitor:

And since
, substituting into the previous equation, we find:
