1. A 5 Ohm resistor is connected to a 9 Volt battery. How many Joules of thermal energy are produced in 7 minutes? 2. The current in a flashlight powered by 4.5 Volts is 0.5 A. What is the power delivered to the flashlight? 3. If the flashlight in the previous problem is left on for 3 minutes, how much electric energy is delivered to the bulb? 4. A 50 Ohm resistance causes a current of 5 milliamps to flow through a circuit connected to a battery. What is the power in the circuit? 5. How many Joules of electric energy are delivered to a 60 Watt lightbulb if the bulb is left on for 2.5 hours?

1. To calculate the energy produced, we first need to find the current using Ohm's law, which is Voltage (V) divided by Resistance (R). In this case, the current I = 9V / 5Ω = 1.8 A.

The power P can then be calculated using the formula P = V * I, which gives us P = 9V * 1.8 A = 16.2 W.

The energy E consumed over time t can be calculated with the formula E = P * t. We need to convert the 7 minutes into seconds by multiplying by 60, thus t = 7 min * 60 s/min = 420 s.

Therefore, E = 16.2 W * 420 s = 6804 J (Joules).

2. The power delivered to the flashlight can be calculated using the formula P = V * I:

P = 4.5 V * 0.5 A = 2.25 W (Watts).

3. To find the electric energy delivered, we again use E = P * t. Time in seconds is 3 minutes times 60, so t = 3 min * 60 s/min = 180 s.

E = 2.25 W * 180 s = 405 J (Joules).

4. First, we convert the current from milliamps to amps: I = 5 mA = 0.005 A.

Now, we use P = V * I to calculate power, but we don't have the voltage. Instead, we can use the formula P = I² * R:

P = (0.005 A)² * 50 Ω = 0.000025 A² * 50 Ω = 0.00125 W or 1.25 mW (Milliwatts).

5. This requires the formula E = P * t again. Convert 2.5 hours to seconds: t = 2.5 hours * 60 min/hour * 60 s/min = 9000 s.

So, E = 60 W * 9000 s = 540000 J (Joules).