Question

This means that the steel bar lost 14900 J of thermal energy. What is the change in temperature of the steel bar? Recall that the steel decreases in temperature, and use the value of 0.49 J/g•°C as the specific heat capacity of steel. The video shows the mass of the steel to be 40.7 g.

Answer 1

`\Delta T=-747.13^0C`

Step-by-step explanation:

Hello,

In this case, the heat is related with the change in the temperature via the heat capacity and the involved mass as shown below:

`Q=mCp\Delta T`

Now, as it is stated that there is an amount of lost heat, such value turn out negative implying that the final temperature is lower than the initial one, in such a way, one computes
`\Delta T` as a measure of the change in the temperature as follows:

`\Delta T=(Q)/(mCp) =(-14900J)/(0.49J/(g^0C)*40.7g)\\ \Delta T=-747.13^0C`

Best regards.

Answer 2

ΔT=-747,13°C

Step-by-step explanation:

Sensible heat is the amount of thermal energy that is required to change the temperature of an object, the equation for calculating the heat change is given by:

Q=msΔT

where:

• Q, heat that has been absorbed or realeased by the substance [J]
• m, mass of the substance [g]
• s, specific heat capacity [J/g°C] (
• ΔT, changes in the substance temperature [°C]

To solve the problem, we clear ΔT of the equation and then replace our data:

Q=msΔT

ΔT=Q/ms

Δ
`T=(-14900 J)/(40,7g*0,49(J)/(gC) )=-747,13`°C

(Note that Q=-14900 J because there is a LOST of thermal energy)

Thus, the change in temperature of the steel bar is -747,13°C, meaning that the temperature of the bar decreases.