A trolley moves from P to Q along a track. By the time it reaches Q, its potential energy is $50\,\text{kJ}$ lower than it was at P. At P, the trolley has a kinetic energy of $5\,\text{kJ}$. As it travels between P and Q, the trolley does $10\,\text{kJ}$ of work against friction. Determine the kinetic energy of the trolley at Q?
- A$35\,\text{kJ}$
- B$45\,\text{kJ}$
- C$55\,\text{kJ}$
- D$65\,\text{kJ}$