If 1200 cal of heat are added to 50 g of water initially at a temperature of 15 oC, what is the final temperature of the water?

Answer 1

the energy needed to increase or decrease the temperature of a given substance is given by
Q = mc(T2-T1)
where
Q = heat (in J or cal)
m = mass (in g)
c = specific heat capacity (in J/g*K or cal/g*K)
T = temperature (in Kelvin)
**change in temperature can have unit degree Celsius or Kelvin,, thus you can use it interchangeably (what i mean is that the units for c can also be J/(g*C))
signs:
Q: (+) when heat is absorbed by substance
Q: (-) when heat is released from substance
for water, c = 1 cal/g*K.
substituting,
1200 = (50)(1)(T2 - 15)
1200 = 50*(T2) - 750
1950 = 50*(T2)
T2 = 39 deg C

hope this helps~ :)