how much energy is stored in a 9 volt battery rated at 10 a hour

Energy = 9 * 10A-h = 90 Watt-hours.

To determine the amount of energy stored in a 9-volt battery rated at 10 amp-hours, you can use the formula:

Energy (in watt-hours) = Voltage (in volts) × Capacity (in amp-hours)

In this case, the voltage of the battery is 9 volts, and the capacity is 10 amp-hours.

So, substituting the values into the formula:

Energy = 9 volts × 10 amp-hours
Energy = 90 watt-hours

Therefore, the energy stored in the 9-volt battery with a 10 amp-hour capacity is 90 watt-hours.