Question
Here's the problem: A 14.4-V battery for a cordless drill can supply 2.0 A ofcurrent. (a) If the drill continuously operated for 5 min,what is the total charge passing through the battery? (b) Whattotal amount of work does the battery do on the charge during thistime? I got (a). On answering (b), I'm thinking sice the netdistance traveled by the charge is 0 since the charge returned tothe battery, the total work is 0, too. Is this correct? Here's the problem: A 14.4-V battery for a cordless drill can supply 2.0 A ofcurrent. (a) If the drill continuously operated for 5 min,what is the total charge passing through the battery? (b) Whattotal amount of work does the battery do on the charge during thistime? I got (a). On answering (b), I'm thinking sice the netdistance traveled by the charge is 0 since the charge returned tothe battery, the total work is 0, too. Is this correct?
Explanation / Answer
A 14.4-V battery for a cordless drill can supply 2.0 A ofcurrent. (a) If the drill continuously operated for 5 min, what is thetotal charge passing through the battery? Qt= I t = 2.0A x 5 x 60 = 600C (b) What total amount of work does the battery do on thecharge during this time? W= Pt = VI t = 14.4 x 2.0 x 5 x 60 = 8640J or W= Vq = 14.4 x 600 = 8640J I got (a). On answering (b), I'm thinking sice the netdistance traveled by the charge is 0 since the charge returned tothe battery, the total work is 0, too. Is this correct? No it is wrong. The charge by moving performed work ( heating,motor, solenoid actuation ...) Please let me know if you have any questions.