A ship RADAR unit uses 315 watts and a radio...

Question 1 of 27070DaInxpsfCb2lj96WfRDd

A ship RADAR unit uses 315 watts and a radio uses 50 watts. If the equipment is connected to a 50 ampere-hour battery rated at 12.6 volts, how long will the battery last?

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Question 1 of 27070

A ship RADAR unit uses 315 watts and a radio uses 50 watts. If the equipment is connected to a 50 ampere-hour battery rated at 12.6 volts, how long will the battery last?

🔍 Key Concepts

• Battery capacity in ampere-hours (Ah) and how to convert that into watt-hours (Wh) using voltage • Power (watts) relationship with energy and time: $P = \frac{E}{t}$ • Adding the total power draw of multiple devices (RADAR + radio)

💭 Think About

• First, figure out how much energy the battery can supply in watt-hours using its ampere-hour rating and voltage. What multiplication will give you that? • Next, add the power used by the RADAR and the radio to find the total power draw. Once you know total watts and total watt-hours available, how do you solve for time? • After you get time in hours from $t = \frac{E}{P}$ , how will you convert the decimal hours into hours and minutes to compare with the choices?

✅ Before You Answer

• Be sure you convert ampere-hours to watt-hours correctly using the battery voltage: $\text{Wh} = \text{Ah} \times \text{V}$ • Double-check you add both loads (315 W + 50 W) before calculating time; don’t treat them separately. • After computing the time in hours, convert the fractional part of an hour to minutes by multiplying by 60, then compare carefully with the options.