Let the masses of the two objects be M1 and M2 and their distance apart = r Therefore the force acting F1 = \( \frac{GM1M2}{r^2}\) for a new distance of r/2, we have a force of F2 = \( \frac{GM2M2}{r/2}\) \(\text{Thus } F1 \times r^2 = GM_1M_1 \text{and}\) F2 \(\times (r/2)^2 = GM_1M_1\) \(\text{Since } GM1M1 = GM_1M_1\) \(\implies F_1 \times r^2 = F2 \times (r/2)^2\) \(\text{Therefore } 200 \times r^2 = F2 \times r^2/4\) F2 = \(\frac{4 \times 200 \times r^2}{r^2} = 800N\)