Answer: [tex]-4.3\ J,\ 9\ J[/tex]
Explanation:
Given
(a)
Heat transfer [tex]Q=-7.9\ J\quad \text{taken}[/tex]
Work done [tex]W=-3.6\ J\quad \text{on the system}[/tex]
Change in the internal kinetic energy is
[tex]\Delta U=Q-W\\\Rightarrow \Delta U=-7.9-(-3.6)\\\Rightarrow \Delta U=-4.3\ J[/tex]
(b)
Heat transfer [tex]Q=1.5\ J\quad \text{given}[/tex]
Work done [tex]W=-7.5\ J\quad \text{on the system}[/tex]
Change in the internal kinetic energy is
[tex]\Delta U=Q-W\\\Rightarrow \Delta U=1.5-(-7.5)\\\Rightarrow \Delta U=9\ J[/tex]
