A certain brand of hot dog cooker applies a potential difference (120 v) to opposite ends of the hot dog and cooks by means of the joule heat produced. if 60 kj is needed to cook each hot dog, what current is needed to cook four hot dogs simultaneously in 3.0 min?

Respuesta :

If your cooker uses 120 volts and the current is 11 amperes, the total power 
it uses is 1320 watts, or 1320 joules every second. If it is divided equally among 
the 3 wieners, each wiener receives 440 watts, or 440 joules of energy every 
second. If a wiener needs 58,000 joules to cook completely, the time needed 
is 58,000 joules divided by 440 J per second, or 131.8 seconds - 2 minutes and 
11.8 seconds. In actual practice, it doesn't take much longer than this, although 
the resistance of the wieners starts out relatively high, about 200 ohms each 
and gradually decreases to about 100 ohms per wiener as the hot dogs cook. 
But for your example here, the time required is 131.8 seconds.