A120-g block of copper is taken from a kiln and quickly placed into a beaker of negligible heat capacity containing 300 g of water. the water temperature rises from 15°c to 35°c.

given ccu = 0.10 cal/g⋅°c, and cwater = 1.00 cal/g⋅°c, what was the temperature of the kiln?
a. 500°cb. 360°cc. 720°cd. 535°c

Answer : The correct option is, (d)

Explanation :

In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.

where,

= specific heat of copper =

= specific heat of water =

= mass of copper = 120 g

= mass of water = 300 g

= final temperature of mixture =

= initial temperature of copper = ?

= initial temperature of water =  

Now put all the given values in the above formula, we get:

Therefore, the temperature of the kiln was,

The temperature of the kiln is 535°C.

(d) is correct option.

Explanation:

Given that,

Mass of block = 120 g

Weight of water = 300 g

Initial temperature = 15°C

Final temperature = 35°C

We need to calculate the temperature of the kiln

Using formula of energy

Put the value into the formula

Hence, The temperature of the kiln is 535°C.

i think it would be 80 km/h because 30 + 50 = 80 (sorry if this not the right answer i'm trying my best)