Answer:
This is the final temperature of water = 398 K
Explanation:
Mass of iron
= 25 gm
Initial temperature of iron
= 398 K
Mass of coffee cup
= 25 ml = 25 gm
Temperature of coffee cup
= 298 K
Specific heat of iron
= 0.449 
Specific heat of water
= 4.18 
From the energy balance principal,
Heat lost by the iron = heat gain by the coffee cup
⇒
×
×
=
×
× 
⇒ 25 × 0.449 ×
= 25 × 4.18 × 
⇒ 0.449 ×
= 4.18 × 
⇒ 398 -
= 9.3 (
- 398 )
⇒
= 9.3
- 3701.4
⇒ 10.3
= 4099.4
⇒
= 398 K
This is the final temperature of water.