To solve this problem it is necessary to apply the law of Malus which describes the change in the Intensity of Light when it crosses a polarized surface.
Mathematically the expression is given as

Where,
= Initial Intensity
I = Final Intensity after pass through the polarizer
= Angle between the polarizer and the light
Since it is sought to reduce the intensity by half the relationship between the two intensities will be given as

Using the Malus Law we have,





Angle with respect to maximum is 
I belive it could be 6.5 but I could be wrong
Answer:We have , a relation in frequency f and wavelength λ of a wave having the velocity v as ,
v=fλ ,
given f=60Hz , λ=20m ,
therefore velocity of wave , v=60×20=1200m/s
Only if a force acts upon it, it can move.
Answer: 166.67km/hr
Explanation:
Given the following :
Distance traveled = 250km
Time taken = 1.5 hours
Recall :
Speed = Distance traveled / time taken
Speed = 250 km / 1.5 hours
Speed = 166. 67 km/hr
Speed in m/s:
166.67km/hr = (166.67 × 1000)m / 3600 s
= 166670m / 3600s
= 46.3m/s