A trolley with mass $600\,\text{kg}$ starts at point P on a slope, with its position $80\,\text{m}$ above ground level, as shown. It is let go from rest and travels down the slope, finally stopping at point Q, which is at height $h$ above ground level. The distance travelled by the trolley along the slope from P to Q is $1.5\,\text{km}$. A steady resistive force of $300\,\text{N}$ acts against the trolley’s motion on the slope. Find $h$.
- A$3.5\,\text{m}$
- B$76\,\text{m}$
- C$79\,\text{m}$
- D$80\,\text{m}$