The value of g at sea level is 9.81 ms^-2.
The boy's mass is constant wherever he is in the universe but his weight will depend on the strength gravity where he is.
By proportion its value on the mountain peak is (360 /400) * 9.81
= 0.9 * 9.81 = 8.83 ms^-2 to nearest hundredth, (answer).
If an equation is dimensionally correct, it does not mean that the equation must be true. On the other hand, when the equation is dimensionally correct, the equation cannot be true. Dimensional analysis is a technique used to check whether a relationship is correct
To solve this problem it is necessary to apply the concepts related to intensity as a function of power and area.
Intensity is defined to be the power per unit area carried by a wave. Power is the rate at which energy is transferred by the wave. In equation form, intensity I is

The area of a sphere is given by

So replacing we have to

Since the question tells us to find the proportion when

So considering the two intensities we have to


The ratio between the two intensities would be

The power does not change therefore it remains constant, which allows summarizing the expression to

Re-arrange to find 



Therefore the intensity at five times this distance from the source is 