Recent content by Art_Vandelay

I want to write a science-fiction story concerning the rapid increase in technology affecting the speed at which spacecraft travel and passengers age (relative to each other). Theoretically, would it be possible that a son leaves a certain time (a number of years) before his father to...

Yes, this is an algebra-based physics course :/ There have been a few others in the class which required calculus, so I was unable to answer them. Thank you so much for your time, effort, and helpfulness! The approximate answer was close enough for the computer program. Thanks again!

I wish I did have some knowledge of calculus, but I do not. I really have no clue how to evaluate the practice problem.

Since dS is infinitesimal, would ΔS be found by multiplying by ΔT?

Unfortunately, I've never used a differential equation before. Is it calculus-based? Here's my attempt: dS*T=mc*dT dS=((.255 kg)(910 J/kg K)(>0K?)/294 K dS=.79 J/K

Oh! Ok, so I would end up with S*T=mc(dT). Would the temperatures then negate each other, or would I need to divide mc by T?

It would almost be equal to zero?

Hmm... Would I use 1/T = dS/dU? But how could I figure out dU without a given pressure?

Would a differential equation be subtracting ΔSCOLD from ΔSHOT? Q = mcΔT = (.255 kg)*(910 J/kgK)*(294 K -278 K) Q = 3713 J ΔSCOLD = Q/T ΔSCOLD = 3713 J / 278 K ΔSCOLD = 13.36 J/K ΔSHOT = 3713 J / 294 K ΔSHOT = 12.63 J/K ΔSnet = ΔSHOT - ΔSCOLD ΔSnet = 12.63 J/K - 13.36 J/K ΔSnet...

Thank you very much! I assume it is supposed to be an ideal hand, possibly Thing from The Addam's Family. :)

Homework Statement Imagine that the temperature of 255 g of aluminum sitting in the sum increases from 278 K to 294 K. By how much has its entropy increased? Homework Equations Q=mcΔT ΔS=Q/T The Attempt at a Solution Q=(255 g)(.90 J/gK)(294 K -278 K) Q=3672 J ΔS=Q/T...

ΔSgal = ((.025 kg)(8.04*104 J/kg))/(29.8+273 K) ΔSgal = 6.64 J/K ΔShand = -((.025 kg)(8.04 * 104 J/kg))/(37+273 K) ΔShand = -6.48 J/K

Would I then divide the QHand by 310 K? I'm not sure how to apply reversibility and irreversibility.

The source of the thermal is the hand, which must be equal to or greater than 29.8°C. So, the changes in entropy of the hand and the gallium are equal and opposite? ΔSgal = ((.025 kg)(8.04*104 J/kg))/(29.8+273 K) ΔSgal = 6.64 J/K ΔShand = -((.025 kg)(8.04 * 104 J/kg))/(29.8+273 K)...

Homework Statement If 25.0 g of gallium melts in your hand, what is the change in entropy of the gallium? What about the change of entropy in your hand? Is it positive or negative? Is its magnitude greater or less than that of the change in entropy of the gallium? The melting...