hw question 4B.3

Brian_Ho_2B
Posts: 221
Joined: Fri Aug 09, 2019 12:16 am

hw question 4B.3

A system's internal energy is increased by 982 J when 492 J of heat was supplied. Because change in energy is equal to the sum of work and heat, it makes sense that work must have been involved for the the change in energy to be that high. Using that equation, it makes sense that 982 J = 492 J + w, shouldn't the work be equal to 490 Joules ? How come the answer is 90 * 10^2 J?

Ipsita Srinivas 1K
Posts: 50
Joined: Mon Jun 17, 2019 7:24 am

Re: hw question 4B.3

I know this isn't a satisfactory answer, but the textbook might just be wrong? It seems weird to me that the work done is approximately 10 times more than the internal energy change! (982 J vs 9000 J)

Luyan Zhang - 2D
Posts: 103
Joined: Sat Jul 20, 2019 12:16 am

Re: hw question 4B.3

Brian_Ho_2B wrote:A system's internal energy is increased by 982 J when 492 J of heat was supplied. Because change in energy is equal to the sum of work and heat, it makes sense that work must have been involved for the the change in energy to be that high. Using that equation, it makes sense that 982 J = 492 J + w, shouldn't the work be equal to 490 Joules ? How come the answer is 90 * 10^2 J?

The solution manual should be wrong. There is no way work done is 9000J.