Question #5b7cb

1 Answer
Jan 25, 2017

60^@"C"

Explanation:

We know that in such interactions heat is gained by one and heat is lost is by the other.

Also that the heat gained/lost is given by

DeltaQ=mst,
where m,s and t are the mass, specific heat and rise or gain in temperature of the object;
and
Delta Q_"lost"=Delta Q_"gained"

Let T be equilibrium temperature. Using CGS units, heat lost by the object
Delta Q_"lost"=mxx0.5xx(80-T) ........(1)

Heat gained by water
Delta Q_"gained"=mxx1xx(T-20) ......(2)

Equating (1) and (2) we get
mxx0.5xx(80-T)=mxx1xx(T-20)
=>0.5(80-T)=(T-20)

Multiplying both sides by 2 we get
(80-T)=(2T-40)
=>3T=80+40
=>T=120/3=40^@"C"