Answer:
Q = 450 J
Step-by-step explanation:
Given that,
Mass of a piece of glass, m = 45 g
The temperature changes from 10°C to 30°C.
The specific heat is 0.5 J/g°C
We need to find heat required to raise the temperature. The formula that is used to find it is given by :

So, the required heat is 450 J. Hence, the correct option is (c).