An electric heater supplies heat to a system at a rate of 100 W. If th

1.	An electric heater supplies heat to a system at a rate of 100 W. If the system performs work at a rate of 75 joules per second, at what rate is the internal energy increasing?
Answer» Rate of heat supplied to the system is 100 W = 100 Js^-1 Rate of work done by the system is 75Js^-1 . From the first law of thermodynamics, we have ∆ Q = ∆ U + ∆ W ……..(1) If the above parameters are observed for a time‘∆ t’, …….(2) where \(\frac{ΔQ}{Δ t}\) is the rate of heat supplied to the system for the given time,\(\)\(\frac{ΔU}{Δ t}\) is the rate of increase in internal energy of the system for the given time and \(\frac{ΔW}{Δ t}\) is the rate of work done by the system in the given time. ∴ From equation (2), we have 100 = \(\frac{ΔU}{Δ t}\) + 75 \(\frac{ΔU}{Δ t}\) = 25 Js^-1 Therefore the internal energy increases at rate of 25 Joules per second.

An electric heater supplies heat to a system at a rate of 100 W. If the system performs work at a rate of 75 joules per second, at what rate is the internal energy increasing?

Answer»

Rate of heat supplied to the system is 100 W = 100 Js^-1

Rate of work done by the system is 75Js^-1 .

From the first law of thermodynamics, we have

∆ Q = ∆ U + ∆ W ……..(1)

If the above parameters are observed for a time‘∆ t’, …….(2)

where \(\frac{ΔQ}{Δ t}\) is the rate of heat supplied to the system for the given

time,\(\)\(\frac{ΔU}{Δ t}\) is the rate of increase in internal energy of the system for the given time and \(\frac{ΔW}{Δ t}\) is the

rate of work done by the system in the given time.

∴ From equation (2), we have

100 = \(\frac{ΔU}{Δ t}\) + 75

\(\frac{ΔU}{Δ t}\) = 25 Js^-1

Therefore the internal energy increases at rate of 25 Joules per second.

Discussion

No Comment Found

Related InterviewSolutions

`S_(H_(2(g)))^(0) = 130.6 J K^(-1) mol^(-1)`, `S_(H_(2)O_((l)))^(0)= 69.9 J K^(-1)mol^(-1)` `S_(O_(2(g)))^(0) = 205 J K^(-1)mol^(-1)`, then the absolute entropy change of `H_(2_((g))) + (1)/(2)O_(2_((g))) rarr H_(2)O_((l))` isA. `-163.2 J mol^(-1) K^(-1)`B. `+163.2 J mol^(-1)K^(-1)`C. `-303 J mol^(-1) K^(-1)`D. `+303 J mol^(-1) K^(-1)`
An intimate mixture of ferric oxide , `Fe_(2)O_(3)`, and aluminium, Al, is used in solid fuel rockets. Calculate the fuel value per gram and fuel value per cc. of the mixture . Heats of formation and densities are as follows `:-` `DeltaH_(f) (Al_(2)O_(3))= 399kcal//mol`, `DeltaH_(f)(Fe_(2)O_(3))= 199kcal//mol` Density of `Fe_(2)O_(3)= 5.2 g//cc`,Density of Al `= 2.7 g //cc.`
Calculate the entropy change for the conversion of2 moles of liquid water at 373K to vapours , if `Delta_(vap)` H is `37.3kJ mol^(-1)`.
Calculae the entropy change fo n-hexane when one mole of it evaporates at 341.7 K `(Delta_(vap) H = 29.0 kJ mol^(-1))`
An ideal gas has volume`V_(0)` at . `27^(@)C` It is heated at constant pressure so that its volume becomes . `2V_(0).`The final temperature isA. `54^(@)C`B. `32.6^(@)C`C. `327^(@)C`D. 150 k
What kind of system does a water filled bucket represents?
When a polyatomic gas undergoes an adiabatic process, its tempertaure and volume are related by the equation `TV^(n) =` constant, the value of `n`will beA. `1.33`B. `0.33`C. `2.33`D. `1`
A monoatomic gas undergoes adiabatic process. Its volume and temperature are related as `TV^(P)` = constant. The value of p will be `{:((1),1.33,(2),1.67),((3),0.67,(4),0.33):}`
For a given reaction `Delta`G obtained was having positive sign convention. State whether the reaction was spontaneous or non-spontaneous.
A gas is contained in a metallic cylinder fitted with a piston.The piston is suddenly moved in to compress the gas and is maintained at this position. As time passes the pressure of the gas in the cylinderA. The pressure decreasesB. The pressure increasesC. The pressure remains the sameD. The pressure may increase or decrease depending upon the nature of the gas