Question

7. An 8.92 kilogram bar of steel at 25°C is heated in order to shape it into a beam. The amount of heat energy

Answer 1

Answer:

1279 °C

Explanation:

Data Given:

Amount of Heat absorb = 5.82 x 10³ KJ

Convert KJ to J

1 KJ = 1000 J

5.82 x 10³ KJ = 5.82 x 10³ x 1000 = 5.82 x10⁶ J

mass of sample = 8.92 Kg

Convert Kg to g

1 kg = 1000 g

8.92 Kg = 8.92 x 1000 = 8920 g

Cs of steel = 0.51 J/g °C

change in temperature = ?

Solution:

Formula used

             Q = Cs.m.ΔT

rearrange the above equation to calculate the mass of steel sample

             ΔT =  Q / Cs.m  .... . . . . . (1)

Where:

Q = amount of heat

Cs = specific heat of steel = 0.51 J/g °C

m = mass

ΔT = Change in temperature

Put values in above equation 1

                ΔT = 5.82 x10⁶ J / 0.51  (J/g °C) x 8920 g

                ΔT = 5.82 x10⁶ J /4549.2 (J/°C)

                ΔT = 1279 °C            

So,

change in temperature = 1279 °C