Complete question:
A light bulb emits light that travels uniformly in all directions. Detailed measurements show that at a distance of 56 m from the bulb, the amplitude of the electric field is 3.78 V/m. What is the average intensity of the light?
Answer:
The average intensity of the light is 0.02 W/m²
Explanation:
Given;
Amplitude of the electric field, E₀ = 3.78 V/m
The average intensity of the light is calculated as follows;

where;
is the average intensity of the light
c is speed of light = 3 x 10⁸ m/s

Therefore, the average intensity of the light is 0.02 W/m²
Answer:
m = 2218.67 kg
Explanation:
It is given that,
Initial velocity, u = 7.5 m/s
Final speed of an object, v = 0 (at rest)
Force, F = 5.2 kN
Time, t = 3.2 s
We need to find the mass of the object. Force acting on an object is given by :
F = ma
m is mass, a is acceleration

So, the mass of the object is 2218.67 kg