Question

A 15.53 kg loose bag of soil falls 5.50 m at a construction site. If all the potential energy of the fall is retained by the soil in the bag, how much will its temperature increase? (csoil = 0.200 kcal/kg oC)

Answer 1

Answer:

The rise in temperature is 0.064 ⁰C

Explanation:

Given;

mass of  loose bag of soil, m = 15.53 kg

height of fall, h = 5.50 m

Potential energy of the fall, U = mgh

                                              U = 15.53 x 9.8 x 5.5

                                              U = 837.067 J = 0.200 kCal

If all the potential energy of the fall is retained by the soil in the bag, then the potential energy of fall is equal to thermal energy of the soil.

U = Q = mcΔθ

where;

Q is quantity of heat  retained by the soil in the bag

m is mass of the loose bag of soil

c is specific heat capacity of the soil =  0.200 kcal/kg ⁰C

Δθ is increase in temperature

Δθ  =  U / mc

Δθ  =  0.2 / (15.53 x 0.2)

Δθ  = 0.064 ⁰C

Therefore, the rise in temperature is 0.064 ⁰C