Joules Experiment Lab- Background information: the objective of lab is to determ

Question

Joules Experiment Lab-

Background information:  the objective of lab is to determine the mechanical equivalent of heat by dropping copper bolts on the floor and measuring the resultant increase in temperature.  We did this, and we were able to raise the copper bolts in temperature by 0.2 degrees celcius.  

Variables:

mass= 32.0 g Copper

height= 1.85 meters

molar mass of Copper= 65.38 g/mole

delta T= 0.2 degrees C

c= 390 j/kg * degrees C

Data:

Using the mass (m), gravity (g), the height we dropped the copper from (h), and n (which is mass/molar mass), i need to find estimated energy.  equation= (mgh)n

Using the specific heat capacity (c), the mass (m), and change in temperature (delta T), I need to find the MEASURED energy.  equation= mc(delta T)

For estimated energy, I am receiving 276.28 J

For measured energy, I am receiving 2.50 J.

See work below...

estimated energy: (32.0 g)(9.8 m/s)(1.8 m)(32.0g/65.38 g/mole)= 276.28 J

measured: (0.032 kg)(390 J/kg C)(0.2)= 2.496 J

Am I doing a calculation wrong???  A difference of 273 J is quite a lot... its surely possible we LOST heat during the lab, but not that much, right?  Am I using the wrong conversions?

thanks.  

Explanation / Answer

you are solving wrong

estimated energy = mgh = (32.0 g)(9.8 m/s)(1.8 m)=565.056 J

measured: =n c dT = (32/65.38)(390 J/kg C)(0.2) =38.17 J

Related Questions

Navigate

• Browse (All)
• Browse J
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.