A forward honzontal force of 50 N is applied to a crate. A second horizontal force o
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In a RC-circuit, with the capacitor initially uncharged, when we connect the battery to the circuit the charge on the capacitor starts to increase following the law:
where t is the time,
is the maximum charge on the capacitor at voltage V, and 
is the time constant of the circuit.
Using this law, we can answer all the three questions of the problem.
1) Using
and 
, the time constant of the circuit is:
2) To find the charge on the capacitor at time
, we must find before the maximum charge on the capacitor, which is
And then, the charge at time is equal to
3) After a long time (let's say much larger than the time constant of the circuit), the capacitor will be fully charged, this means its charge will be
. We can see this also from the previous formule, by using 
:
where t is the time,
Using this law, we can answer all the three questions of the problem.
1) Using
2) To find the charge on the capacitor at time
And then, the charge at time
3) After a long time (let's say much larger than the time constant of the circuit), the capacitor will be fully charged, this means its charge will be
Answer:
The doppler effect equation is:
In the equation we have frequencies, but then we have the wavelengths of the lights, remember the relation:
v = f*λ
then:
f = v/λ
and v is the speed of light, then:
f = c/λ
where:
f' is the observed frequency, in this case, is equal to f = (3*10^17nm/s)/550 nm
f is the real frequency, in this case, is (3*10^17nm/s)/650 nm
vs is the speed of the source, in this case, the source is not moving, then vs = 0 m/s.
v is the speed of the wave, in this case, is equal to the speed of light, v = 3*10^8 m/s
v0 is your speed, this is what we want to find.
Replacing those quantities in the equation, we get:
(3*10^17nm/s)/550 = (3*10^8 m/s + v0)/(3*10^8 m/s)*(3*10^17nm/s)/650 nm
(650nm)/(550nm) = (3*10^8 m/s + v0)/(3*10^8 m/s)
1.182*(3*10^8 m/s) = (3*10^8 m/s + v0)
1.182*(3*10^8 m/s) - (3*10^8 m/s) = v0 = 54,600,000 m/s
So your speed was 54,600,000 m/s, which is a lot.