The correct option is B which is 15 g.
Given to us:
the heat [tex]Q= 350\ Joules[/tex],
the specific heat [tex]c= 1.2\ J/g\ ^o C[/tex],
the lower temperature [tex]t_1= 10^o C[/tex],
the higher temperature [tex]t_2= 30^o C[/tex],
Formula for specific heat:
[tex]Q=mc(\Delta T)[/tex]
where,
[tex]m[/tex] is the mass,
[tex](\Delta T)[/tex] is the temperature difference,
Putting in the values;
[tex]350=m\times 1.2\times (30-10)\\\\m= \dfrac{350}{1.2\times (30-10)} \\\\m=14.5833 grams[/tex]
Hence, the mass is 14.5833 grams. therefore, the correct option is B which is 15 g.
To know more visit:
https://brainly.com/question/1209542