How Does Temperature Affect the Period of a Pendulum?

[jabbie3]

Homework Statement

A simple pendulum uses a steel wire as the string. The length of this wire is 1.4 m at room temperature. If the temperature is increased by 11.9 degrees C, the length of the wire increases by 1.69 mm . What is the change in period of the pendulum?

Homework Equations

T=2pi*$$\sqrt{L/g}$$

The Attempt at a Solution

L_final=1.4+.00169=1.40169m
L_initial=1.4m
g=9.8 m/s²

$$\Delta$$T=T_final-T_initial

=2pi*$$\sqrt{1.40169/9.8}$$-2pi*$$\sqrt{1.4/9.8}$$

=2.376253765-2.374820823=.0014329416 s

This is wrong :(. What am I doing wrong?

 

[Dr.D]

Check the units on your "relevant equation." I think you will find a problem there.

 

[nlightner]

Your solution looks correct to me. However, there may be a rounding error in your final answer. Make sure to use all significant figures in your calculations and round your final answer to the appropriate number of significant figures. Also, double check that you are using the correct value for g, which may vary slightly depending on location and elevation.