What Mass Should Be Used in Joule's Experiment to Deliver 1.00 kcal?

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SUMMARY

The discussion focuses on calculating the mass required in Joule's experiment to deliver 1.00 kcal to water using a descending mass. The formula used is U = mg(delta)h, where g is the acceleration due to gravity (9.80 m/s²) and delta h is the height (1.23 m) multiplied by the number of descents (30). The correct mass calculated is approximately 11.57 kg, confirming the conversion of 1 kcal to 4186 joules is accurate and the calculations align with the principles of potential energy.

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Homework Statement



An experiment is conducted with a basic Joule apparatus, where a mass is allowed to descend by 1.23 m and rotate paddles within an insulated container of water. There are several different sizes of descending masses to choose among. If the investigator wishes to deliver 1.00 kcal to the water within the insulated container after 30.0 descents, what descending mass value should be used? Let g = 9.80 m/s2. (need answer is in kg)

Homework Equations



U=mg(delta)h

The Attempt at a Solution



1kcal=m(9.8)*30*1.23
4186 =m(361.62)
4186/361.62=m
11.576=m


Did I do this correctly?

Thanks in advance.
 
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^ assuming your conversion of kcal to joules is correct that seems like a model solution to me.
 
1 Kcal = 4186 joules
As you say potential energy = mgh
Rememebr to put the units in:

E = m g h
4186 J = m kg * 9.81 m/s^2 * (30*1.23)m
Check units, J = N m = kg m/s^2 m

so m = 4186 / (9.8 * 30 * 1.23) = 11.57kg
 
Thanks for the reminder!
 

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