How to Calculate Error in a Pendulum Clock at Different Temperatures"

In summary, The question asks about the magnitude of error in seconds per hour for a pendulum clock made of brass that is designed for 23 °C but operates at 0.0°C. The linear expansion coefficient of brass is provided and the period of oscillation and change in length of the pendulum are known, but it is unclear how to relate them to solve the problem. The relative errors are related by a formula involving the period and length of the pendulum.
  • #1
squanto
1
0
I am trying to solve this question..

A pendulum clock with a pendulum made of brass is designed to keep accurate time at 23 °C. If the clock operates at 0.0°C, what is the magnitude of its error, in seconds per hour (use a minus sign to indicate slowing down)? The linear expansion coefficient of brass is 19 x 10-6 /C°.

I know that the the period of oscillation is

T= 2pi * sqrt( L /g)

and that the change in the length of the pendulum
is

-4.37E-4 m

I just don't know how to relate the two to solve
Any help is appreciated.
 
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  • #2
Because T varies as the square root of L the relative errors are related by
[tex]\frac {\delta T}{T} = \frac {1}{2} \frac {\delta L}{L}[/tex]
 
  • #3


To calculate the error in a pendulum clock at different temperatures, we need to consider the effects of temperature on the length of the pendulum. As stated in the question, the linear expansion coefficient of brass is 19 x 10^-6/C°. This means that for every 1°C increase in temperature, the length of the pendulum will increase by 19 x 10^-6 meters.

To calculate the error at a specific temperature, we can use the formula:

Error (seconds per hour) = (change in length of pendulum / original length of pendulum) * (change in temperature / original temperature) * 3600 seconds

In this case, we are trying to find the error at 0.0°C, so the change in temperature is -23°C (since the original temperature is 23°C). The change in length of the pendulum is -4.37 x 10^-4 meters, as stated in the question.

Substituting these values into the formula, we get:

Error (seconds per hour) = (-4.37 x 10^-4 / original length of pendulum) * (-23 / 23) * 3600 seconds

Now, we need to find the original length of the pendulum. We can use the formula for the period of oscillation:

T = 2π * √(L/g)

Rearranging this formula to solve for L, we get:

L = (T/2π)^2 * g

Since the clock is designed to keep accurate time at 23°C, we can use the original period of oscillation at this temperature, which is 2 seconds. The acceleration due to gravity, g, is a constant of 9.8 m/s^2.

Substituting these values into the formula, we get:

L = (2/2π)^2 * 9.8 m/s^2 = 0.992 m

Now, we can substitute the original length of the pendulum into the formula for error:

Error (seconds per hour) = (-4.37 x 10^-4 / 0.992) * (-23 / 23) * 3600 seconds

Simplifying, we get:

Error (seconds per hour) = -0.784 seconds per hour

Therefore, at 0.0°C, the pendulum clock will slow down by 0.784 seconds per hour
 

Related to How to Calculate Error in a Pendulum Clock at Different Temperatures"

1. How does a pendulum clock work?

A pendulum clock works by using a swinging pendulum as a timekeeping mechanism. The pendulum's movement is controlled by a series of gears and weights, which regulate the clock's accuracy and keep it ticking.

2. How accurate is a pendulum clock?

When properly maintained, a pendulum clock can be very accurate, typically losing or gaining only a few seconds per day. However, its accuracy can be affected by external factors such as temperature, air pressure, and motion.

3. Why do pendulum clocks need to be wound?

Pendulum clocks need to be wound because they use a weight-driven mechanism to keep time. The weights provide the energy needed to power the gears and keep the pendulum swinging. Winding the clock raises the weights and allows the clock to continue running.

4. Can a pendulum clock run forever?

No, a pendulum clock cannot run forever. Eventually, the weights will reach the bottom, and the clock will stop. It also requires regular maintenance and adjustments to keep it running accurately.

5. What is the significance of the length of a pendulum in a clock?

The length of a pendulum in a clock is crucial for its accuracy. The longer the pendulum, the slower it swings, resulting in a longer time interval between ticks. This allows for more precise timekeeping, as smaller fractions of time can be measured.

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