Question

If you pour equal amounts of scalding hot water into different metallic cups of equal temperature, which cup will heat up the most?
Rank the cups from hottest to coldest.
Rank from warmest to coolest final temperature.

500-g cast iron cup
500-g gold cup
750-g cast iron cup

Answer 1

Answer:

Explanation:

It is given that we pour equal amount of scalding hot water into different metallic cups.

$Q=mc\Delta T$

where Q=heat supplied

m=mass of substance

c=specific heat

$\Delta T$=Rise in temperature      

We know that specific heat of gold is greater than cast iron ,therefore, for same mass of  cup temperature rise will be maximum in cast iron cup

so 750 gm cup temperature rise is less as mass is more

Temperature rise will be maximum in 500 g cast iron cup and least in 500 g gold cup

500 g CI cup>750 g CI cup > 500 g gold cup

Answer 2

Answer:

500-g gold cup  > 500-g cast iron cup > 750-g cast iron cup

Explanation:

From the heat energy equation we know that:

$Q=m.c.\Delta T$

where:

$Q=$ heat transfer from or to the body

$m=$ mass of the body concerned

$c=$ specific heat of the material of the concerned body

$\Delta T=$ temperature difference between the bodies in contact

Since the gain in temperature of the cup is proportional to the amount of heat which the water holds and is inversely proportional to the mass of the cup and the specific heat capacity of the material.

We have the specific heat of gold less than the specific heat of the cast iron therefore for the same mass of gold and cast iron we require lesser heat in case of gold to increase its temperature by 1 kelvin.