Question

How much heat is needed to change the temperature 7.5° C on water with amass of 125 g? c= 4.18

Answer 1

The equation that gives the heat for a change in temperature is:

`Q=m\cdot c\cdot\Delta T`

Where Q is the heat, m is the mass, c is the specific heat capacity and ΔT is the change in temperature.

So, we can calculate Q by substituting the given values:

`\begin{gathered} \Delta T=7.5\degree C \\ m=125g \\ c=4.18J/(g\degree C) \end{gathered}`

So, we have:

`\begin{gathered} Q=125\cancel{g}\cdot4.18J/(\cancel{g}\cancel{\degree C})\cdot7.5\cancel{°C} \\ Q=125\cdot4.18\cdot7.5J \\ Q=3918.75J\approx3900J \end{gathered}`

So, the heat needed is 3918.75 J or approximately 3900 J.