Gravitational field intensity is the force experienced by 1 Kg mass in the gravitational field of any massive body. Mathematically, the magnitude of \(E_g=\frac{GM}{r^2}\) Since gravitational Force acts toward the center of the earth
Gravitational Field Intensity (Eg) = -GM/r2 \(\widehat r\)
Solution:
Let, radius of earth be Re = 63.8 x 10^5 m
Let, the gravitational field intensity of earth before squeezed be Ei
Now according to the formula, \(E_i=\frac{GM}{R_e^2}\)
Or, \(E_i=\frac{GM}{{(63.8\times10^5)}^2}\) ---------- (1)
Now gravitational field intensity of earth after being squeezed to the size of moon is
\(E_f=\frac{GM}{R_m^2}\) [ Rm is the radius of moon = 1.7 x 10^6 m]
Or, \(E_f=\frac{GM}{{(1.7\times10^6)}^2}\) --------- (2)
Now dividing equation 2 by equation 1 we get,
\(\frac{E_f}{E_i}=\frac{\displaystyle\frac{GM}{R_m^2}}{\displaystyle\frac{GM}{R_e^2}}\)
Or, \(\frac{E_f}{E_i}=\frac{R_e^2}{R_m^2}\)
Or, \(\frac{E_f}{E_i}=\frac{{(63.8\times10^5)}^2}{{(1.7\times10^6)}^2}\)
Or, \(\frac{E_f}{E_i}=14\)
∴ \(E_f=14E_i\)
Hence the gravitational field intensity of the earth surface will increase by around 14 times, if earth were to squeezed to the size of the moon.