Answer:
Explanation:
The intensity of polarised light after polarization through angle θ
I = I₀ cos²θ
Here θ = 23 for first polariser
Intensity after first polarisation
= I₀ cos²23 = .846 I₀
For second polariser θ = 90 - 23 = 67 degree
Intensity after second polarisation
= .846 I₀ cos²67 = .13 I₀ .
Choices A, B, and D are false statements.
I think choice-C is trying to say the right thing, but it
might have gotten copied incorrectly.
Electric fields and electric forces both increase as the distance
decreases, and decrease as the distance increases.
Answer:
(a) 
(b) 
Explanation:
We can derive the initial speed of the rock from the equation of the speed in function of the time:

Using the given values for the speed at time t=1.7s, we get:

In words, the speed of the rock at launch is 34m/s (a).
Next, we use this to calculate the speed at t=4.9s:

This means that the speed of the rock at 4.9s after the launch is 14m/s (b), and the negative sign means that it is moving downwards.
Answer:
Yes, I'm pretty sure it is. That's why I don't click on it!
Answer:
His average speed.
Explanation:
Average speed = Total distance travelled / total time .
In the given case odometer measures total distance travelled . Dividing it by time will give average speed .
Average velocity can not be the answer as it is measured by dividing displacement by time . Displacement here is zero because initial and final point are same . Instantaneous velocity is given by the speedometer . It keeps on changing all the time . It is actually speed at a particular point of time . It can not be average velocity or speed .