Question 3-61I3

To determine how long the battery will last, first calculate the total power consumed by both devices, then find the total current drawn from the battery, and finally divide the battery's capacity by this current. 1. **Calculate total power consumption:** Total Power (P) = RADAR power + Radio power P = 315 watts + 50 watts = 365 watts 2. **Calculate total current drawn from the battery:** Using the formula P = V * I (Power = Voltage * Current), we can find Current (I) = P / V. I = 365 watts / 12.6 volts = 28.968 amperes 3. **Calculate battery life:** Battery Life (Time) = Battery Capacity (Ah) / Total Current (A) Time = 50 ampere-hours / 28.968 amperes = 1.726 hours 4. **Convert fractional hours to minutes:** 0.726 hours * 60 minutes/hour = 43.56 minutes. Therefore, the battery will last approximately 1 hour and 43 minutes. Option B is incorrect as it represents the calculated current draw, not the battery life. Options C and D are incorrect as they result from miscalculations of power, current, or time. This question tests basic electrical power (P=VI) and battery capacity (Ah=I*t) calculations, which are fundamental for powering amateur radio equipment.