I thought you were going to ask for the resistance of the unknown
series resistor. Since you only want the equivalent resistance of the
circuit, you don't even need to know the resistance of the lamp.
I = E / R
Current through the circuit = (voltage of the battery) / (circuit resistance).
0.5 = (12) / R
Multiply each side by 'R' : (0.5) R = 12
Multiply each side by 2 : <em>R = 24 ohms</em>
(Since the resistance of the lamp is 10 ohms, the
unknown series resistor is the other 14 ohms.)
The time to distance ratio is 2.1:1 , making the first time 5 seconds, the first distance 18.9 m, and the second time 15 seconds. I hope this helps!
That's what happens if there is more than one force acting on the
object, and the forces are balanced, that is, they all "cancel out".
Think of the rope in a Tug-'o-War. It has 50 musclebound football guys
all pulling the rope to the west, and 150 strong cheerleaders all pulling
the rope to the east. The total force to the west is exactly equal to the
total force to the east, and the rope doesn't move at all. The forces on it
are balanced, and the effect on its motion is the same as if there were
no force on it at all.
I believe it is Acoustics, the real name for it would be like Reverberation. But go with Acoustics. :)
The gravitational potential energy
gpe = mgh
