Calculating Current Flow in a Short-Circuited Battery

[kirsten_2009]

Homework Statement

[/B]
A 1.5 volt battery is short-circuited by a 2–meter long wire having a resistance of 0.02 ohm per meter. How large is the current flowing through the wire (before the wire or the battery burn out)?

Homework Equations

Voltage = Ampere x Resistance
Ampere = Voltage/Resistance

The Attempt at a Solution

Ampere = 1.5 V / 0.02 ohm x 2 m (0.04 ohm/m)
Ampere = 37.5 Amperes

 

[phinds]

"Ampere = 1.5 V / 0.02 ohm x 2 m (0.04 ohm/m)" is not really a good expression but yes, your answer is right and I think you clearly understand what you are doing even if you did not express it well mathematically. Without units, it's just 1.5/.04 = 37.5

You should express it mathematically in a way that makes the units come out right

 

[Mark44]

Homework Statement

[/B]
A 1.5 volt battery is short-circuited by a 2–meter long wire having a resistance of 0.02 ohm per meter. How large is the current flowing through the wire (before the wire or the battery burn out)?

Homework Equations

Voltage = Ampere x Resistance
Ampere = Voltage/Resistance

The Attempt at a Solution

Ampere = 1.5 V / 0.02 ohm x 2 m (0.04 ohm/m)
Ampere = 37.5 Amperes

Your answer is fine, but your work is a little off in the units. In the first line above, you have .02 ohm x 2 m, and get .04 ohm/m. The numbers are right, but the units aren't. They should be .02 ohm/m x 2 m, which results in .04 ohm, not ohm/m.

Some suggestions:
Instead of writing this -- 1.5 V / 0.02 ohm x 2 m (0.04 ohm/m) -- as 1.5 V /(0.02 ohm/m x 2m). In other words, use parentheses around the two factors in the denominator. If you write a/bc, most will interpret this as (a/b) times c, rather than a divided by (bc).

 

[kirsten_2009]

Oh O.k I see...thank you very much, I will adjust my units :)

 

[HalfLostAndSearching]

The current flowing through the wire in this scenario would be 37.5 Amperes. This is a very high current, which could potentially cause the wire or the battery to burn out. It is important to note that short-circuiting a battery can be dangerous and should be avoided. In a real-world scenario, the current flow may also depend on the internal resistance of the battery and other factors such as temperature. It is always important to use caution and proper safety protocols when conducting experiments or calculations involving electrical circuits.