The line is called equator.
Answer:
Energy lost due to friction is 22 J
Explanation:
Mass of the ball m = 4 kg
Initially velocity of ball v = 6 m/sec
So kinetic energy of the ball 

Now due to friction velocity decreases to 5 m/sec
Kinetic energy become

Therefore energy lost due to friction = 72 -50 = 22 J
Answer:Same magnitude
Explanation:
When ball is dropped from shoulder height h then velocity at the bottom is given by

if it makes elastic collision then it will acquire the same velocity and riser up to the same height
If m is the mass of ball then impulse imparted is given by


Thus impulse imparted by gravity and Floor will have same magnitude of impulse but direction will be opposite to each other.
Answer:
phase difference = π / 2
constructive interference
Explanation:
Given data
wavelength = 420 nm
1st beam = 105 nm
path difference = 105 nm
to find out
phase difference and interference pattern of the two beams
solution
we use here equation of phase difference that is
phase difference = 2π / wavelength × Δx
put here value
phase difference = 2π / 420 × 105
phase difference = π / 2
and
we know that here path difference Δx is the integral multiple of the wavelength so it will be constructive interference
Δx is wavelength / 4