A metal is heated up to a temperature of 500∘C. It is then exposed to...

Stefan Hendricks

Stefan Hendricks

Answered

2021-12-29

A metal is heated up to a temperature of 500C. It is then exposed to a temperature of 38C. After 2 minutes, the temperature of the metal becomes 190C. When will the temperature be 100C?

Answer & Explanation

puhnut1m

puhnut1m

Expert

2021-12-30Added 33 answers

Initial temp =500C
Ta=Ambient temp=38C
After 2 min, temp =190C
Calculate: Time when temp reaches to 100C
dTdt=K(TTa)
dTTTa=K dt
500190dTTTa=K02dt
t=0,T=500C
t=2,T=190C
[ln(TTa)]500190=K(20)
ln23176=2Kk=12ln23176
dTTTa=Kdt
t=0,T=500C
T=t,T=100C
500100dTTTa=k0tdt
[ln(TTa)]500100=k(t0)
ln(10038)ln(50038)=kt
ln(1003850038)=12ln(23176)t
Answer: t=3.61 minute
Neunassauk8

Neunassauk8

Expert

2021-12-31Added 30 answers

The mean temperature of the metal as it cools from 500C to 190C is,
θ=500+1902
θ=6902=345C
The rate of decrease of temperature is,
5001902=155 deg Cmin
According to the Newtons
karton

karton

Expert

2022-01-09Added 439 answers

Ta=Ambient temp=38C=190C100CdTdt=K(TTa)dTTTa=K dt500190dTTTa=K02dtt=0,T=500Ct=2,T=190C[ln(TTa)]500190=K(20)ln23176=2Kk=12ln23176dTTTa=Kdtt=0,T=500CT=t,T=100C500100dTTTa=k0tdt[ln(TTa)]500100=k(t0)ln(10038)ln(50038)=ktln(1003850038)=12ln(23176)tAnswer: t=3.61 minute

Do you have a similar question?

Recalculate according to your conditions!

Ask your question.
Get your answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?