Answer:
option (B)
Explanation:
Intensity of unpolarised light, I = 25 W/m^2
When it passes from first polarisr, the intensity of light becomes
Let the intensity of light as it passes from second polariser is I''.
According to the law of Malus
Where, θ be the angle between the axis first polariser and the second polariser.
I'' = 11.66 W/m^2
I'' = 11.7 W/m^2
Answer:
A. 3.3 m
Explanation:
Here, we have to use conservation of energy principle.
When the ball is at maximum height, the instantaneous velocity at that point is 0 m/s. So, the kinetic energy of the ball is also 0 at the maximum height. Thus, at maximum height, the energy possessed by the ball is gravitational potential energy only.
Now, when the ball reaches the ground, all the gravitational potential energy changes into kinetic energy because of the conservation of energy.
Therefore, the energy transformation can be given as:
Decrease in potential energy = Increase in Kinetic energy
Decrease in potential energy is given as:
Increase in kinetic energy is given as:
Therefore,
Now, plug in 8 for , 9.8 for
and solve for height
. This gives,
Therefore, the maximum height reached by the ball is 3.3 m.