Observations must be
subjective
objective
biased
deductive

Objective

An observation is the outcome of the experimentation procedure. It is based upon the measurements and virtual evidences obtained while applying procedures. The observations should be objective that means they should be noted or recorded as such without any manipulation. An analyst should not make assumptions and the observation should be unbiased for a particular parameter because results will not be accurate.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000