Transcript Physcs 2 Lecture Notes

At ignition (to), explosive fuel combustion
carries the rocket from its stationary
position near the space outpost by
producing a ~steady thrust F over the
t seconds of the brief burn.
Select the best graphical representation of the ship’s speed:
to
to+t
to
to+t
to
to+t
to
to+t
to
to+t
to
to+t
At time t=to seconds, when
the capacitor is fully charged,
the switch is toggled as shown.
Select the graph best representing
the charge, Q, remaining on the
capacitor.
to
to
to
to
to
to
A simple circuit consists of a resistor R,
a capacitor C charged to a potential V,
and a switch that is initially open but
then closed. The moment the switch is
closed, the current in the circuit is
1) V / R
2) zero
3) need more information
A simple circuit consists of a resistor R,
a capacitor C charged to a potential V,
and a switch that is initially open but
then closed. The moment the switch is
closed, the current in the circuit is
1) V / R
2) zero
3) need more information
A long time after the switch is closed, the current in the
circuit is
1) V / R
2) zero
3) need more information
Three different capacitors are charged up and then
allowed to discharge through the same resistor. The
voltage versus time across each capacitor during
discharge is shown below. Which capacitor has the
largest capacitance?
1) A
V
2) B
3) C
A
B
C
t
4)all the same
Three different capacitors are charged up and then
allowed to discharge through the same resistor. The
voltage versus time across each capacitor during
discharge is shown below. Which capacitor has the
largest capacitance?
1) A
V
B
A
2) B
3) C
4)all the same
Since the voltage falls 63% of the way to 0 V in time t = 
Slower fall off means greater 
Since  = RC  C =
/R
Greater   greater C
C
t
In the circuits below, all EMF s are the same, all resistors are the same
and all capacitors are the same. In which of the circuits will the
capacitor charge up the fastest?
1) A
2) B
3) C
4) all the same
In the circuits below, all EMF s are the same, all resistors are the same
and all capacitors are the same. In which of the circuits will the
capacitor charge up the fastest?
1) A
2) B
3) C
4) all the same
In which circuits will the capacitor have the greatest charge?
1) A
2) B
3) C
4) all the same
In the circuits below, all EMF s are the same, all resistors are the same
and all capacitors are the same. In which of the circuits will the
capacitor charge up the fastest?
1) A
2) B
 = RC
3) C
4) all the same
Equivalent R smallest in circuit 1
In which circuits will the capacitor have the greatest charge?
1) A
2) B
3) C
4) all the same
Q = CV When capacitor charged, I = 0, so V across resistor = 0
Loop rule says V across capacitor is  for each capacitor