1. In the circuit ina 20-ohm resistor sits inside 109 gg of pure water that is surrounded by insulating Styrofoam

If the water is initially at temperature 11.8 C, how long will it take for its temperature to rise to 57.5 C? Use 4190J/kgCas the specific heat of water, and express your answer in seconds using three significant figures.

2. A large capacitor has a charge + q on one plate and q on the other. At time t=0, the capacitor is connected in series to two ammeters and a light bulb. Immediately after the circuit is closed, the ammeter connected to the positive plate of the capacitor reads IP and the ammeter connected to the negative plate of the capacitor reads IN

Each ammeter reads positive if current flows through the circuit in a clockwise direction (from the + to the terminal of the meter).

Light bulbs are often assumed to obey Ohm's law. However, this is not really true because their resistance increases substantially as the filament heats up in its "working" state.

A typical flashlight bulb at full brilliance draws a current of approximately 0.5 A when connected to a 3-V voltage source. For this problem, assume that the changing resistance causes the current to be 0.5 A for any voltage between 2 and 3 V.

Suppose this flashlight bulb is attached to a capacitor as shown in the circuit from the problem introduction. If the capacitor has a capacitance of 3 F (an unusually large but not unrealistic value) and is initially charged to 3 V, how long will it take for the voltage across the flashlight bulb to drop to 2 V (where the bulb will be orange and dim)? Call this time tbright

Express tbright numerically in seconds to the nearest integer.