An incoherent led source is directly against the fibre and covers the entire core area at the beginning of a step-profile multimode fibre and excites equally all possible forward propagating bound, refracting and tunnelling ray path directions within the core. the core index is 1.475, the cladding index is 1.465 and the core radius is arbitrary. by considering the value of the complementary critical angle, determine the percentage of the total power entering the core from the led that excites all bound ray directions. [hint: the solid angle subtended by a cone of semi-vertical angle w is 2p(1-cosw)]

be subject to a force andchange its motion

dec 23, 2016 - a load of bricks weighing 680 n a distance of 10 m across a parking lot. if if the worker pushes the cart with a constant force of 209 n, what work= force x distance = 220 n x 10 m = 2200 n.m = 2200 j i don't know where the person got it from, but the initial part, work= force x distance me.

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min