Answer:
The transmitted intensity through all polarizers is 
Explanation:
According to Malu's law the intensity of a polarized light having an initial intensity 
is mathematically represented as
Now considering the polarizer(The polarizing disk) the equation above becomes
Where n is the number of polarizers
Substituting 
for the initial intensity 3 for the n and 20° for the angle of rotation
Reflecting telescope. Reflecting telescopes tend to have larger objective (due to the use of mirrors, mirrors are a lot cheaper than lenses) and have the ability to collect more light, while refracting telescopes are limited to objective lenses with smaller diameters due to their structural limitations (chromatic abbreviation, for example). Therefore, reflecting telescopes should be better at viewing faint distant stars
Because it doesn't use energy it uses mechanical and kinetic
do not forget to change grams to kilograms and if it were in centimeters convert them to meters.
