An engine draws 180 A from a 12 V battery for 2.0 s. How much power is used?

Answer 1

Power P (watts) = E (voltage) x I (amps). If what you're really after is power, the time is not relevant to the problem. Power is a rate of doing work, and in your example, P = 2160 Watts.

If you're after work done, however, then the work W (Joules) = P (watts) x t (seconds). In this example, the energy used would be 4320 Joules.

Answer 2

12V is good. If you are having cold start problems then it's not the volts that matter except for seeing if the battery is still good. To fix the cold start problem then you will need a battery that has more cold crank amps.( CC amps). The other problem that you may have is the starter may be dragging. Meaning it's taking more amps to run the starter. If you don't want to change out the battery then put a 100 watt light bulb in the engine compartment not touching anything and as close to the battery as you can get. This will keep the battery and engine a little warmer than the outside temp

Answer 3

Power of the engine, P=IV= 180 x 12 = 2160 Watt or 2.16 kW

Since the engine only work for 2.0 s

the answer to arrive is the energy being used,

i.e E = Pxt = 2160 x 2 = 4,320 Joule or 4.32 kJ

Answer 4

Seems to me the capacity of the battery is in question. A known good battery with 600 Amp hours would work differently than a super heavy duty @ 1000 amps, or an el cheapo at 400 cap.

The higher storage capacity the more even the currant flow. A battery with a heavy draw is not going to provide a steady flow, since it is electro chemical action.
Temperature will also be a factor. -20 degrees, -50 etc. And last but not least, the battery will heat up as well.

Opps, sorry! I missed the word "engine". Engines produce energy, not draw. Motors use energy and the torque factor needs to be known.............

Answer 5

Ah, words. Dangerous words. 180 A times 12 V gives 2160 watts. That is POWER. Stirring in the element of time gives us 4320 watt-seconds or 0.0012 KW-hrs (that is the customary unit), but please note that this is not POWER. It is WORK. Voltage is the POTENTIAL to generate POWER which can do WORK. Sneaky physics distinctions, but it will make the difference between an A and an F.

Answer 6

P = EI
The Power is 180 x 12 =
2160 watts. The time has nothing to do with the problem.

Answer 7

Power, P = VI = 12 x 180 = 2160 watts

If you mean energy
E = P x time = 2160 x 2 = 4320 joules

Answer 8

Power has nothing to do with time. The power dissipated during this time is 2.160 KW. The energy used would be 4.32 KWS

P=IxE
E=PxT

Answer 9

180 * 12 * 2 = 4320 Watt seconds (Joules)

Or 4.32 Kj
Or 4.32 Kw/s
Or 1.2 Watt hours

Answer 10

Power (in watts) = current (in amps) X e.m.force (in volts)

So: 12 volts X 180 amps. = 2.16 kw

Answer; 2.16 kilowatts