Answer & Explanation:
The acceleration due to gravity is about 10 m/s^2.
That means a the speed of a falling object will increase by 10 m/s every second that it falls.
We know that the lamp hits the ground at 15 m/s.
That means the lamp has been falling for
[tex]\frac{15 m/s}{10 m/s^{2} } = 1.5 s[/tex]
Now we use the formula [tex]h = \frac{1}{2} gt^{2}[/tex] to calculate the height, where
h is the height
g is the acceleration due to gravity and
t is the time taken to fall a height of h.
h = 1/2 x 10 x 1.5^2 = 11.25 m