(a) consider an electromagnetic wave of the form e eolicos(kz - wt)0.8j sin(kz - wt + ¢) _ (i) discuss the effect of the phase d on the state of polarisation of the wave. (ii) for what value(s) of the phase 0 is this wave linearly polarised? (ii we pass that field through a half-wave plate. for the phase value you obtained in (ii), at what relative angle polarisation state into 'horizontal' (0°)? explain your answer. must the axis of this half-wave plate be oriented to turn the (b) (advanced) a sheet of plastic, uniformly 1.5 mm polarizers which are illuminated from the back with 532 nm bright bands appears. how much does the relative difference in the index of refraction in the plastic (nn1) have to vary in order to produce the half-wave plate behaviour needed to create successive dark and bright bands? show all working thick, is viewed between crossed linear light.

-4 on

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2

0 = 0.40 / 0 = 0

= 0.20 = 9.80 ⁄2 =?

=0 , = = 0.20 =0.50 0 0.40 ⁄

=0−122 =0−12(9.80 ⁄2)(0.50)2 =1.2