The solution for this problem is: In the figure, you now know that total length of the kerosene column
So at x – xPatm + Pkg(H0 th) = Pa + Pwgh
Now H0 + h = 20 + 91.1 mm = 111.1 mm
Therefore = Pkg 0.1111 – P2g= h = 56 x 0.111 – 98 / 1000 x 9.81= 0.081 m or 81 mn
Therefore H0 = 111.1 - 81= 30.1 mm
Answer:
Distance will be 49.34 m
Explanation:
We have given wavelength 
Diameter of the antenna d = 2.7 m
Range L = 7.8 km = 7800 m
We have to find the smallest distance hat two speedboats can be from each other and still be resolved as two separate objects D
We know that distance is given by 
So distance D will be 49.34 m
Density =mass/volume 120/200 =0.6 g/cm