Answer:
95.16 m
Step-by-step explanation:
L = Range of radar = 7.8 km
= Wavelength = 2 cm
d = Diameter of antenna = 2 m
D = Distance
We have the relation
![(D)/(L)=1.22(\lambda)/(d)\\\Rightarrow D=1.22(L\lambda)/(d)\\\Rightarrow D=1.22(7800* 0.02)/(2)\\\Rightarrow D=95.16\ m](https://img.qammunity.org/2020/formulas/physics/college/2carrp77tmt51vxu7tjmdc7wyk9ocvax68.png)
The smallest distance in meters that two speedboats can be from each other and still be resolved as two separate objects by the radar system is 95.16 m