If a ray of light hits the surface of a sheet of glass, some light will be reflected by the surface of the glass. However, much of the light will pass through the glass, because glass is transparent. ... This 'bending of a ray of light' when it passes from one substance into another substance is called refraction.
Answer:
Answer in below and plz mark me as brainlist plz
Explanation:
The rate of change of momentum =tm(v−u) Rate of change of momentum = force applied. Force∝tm(v−u) Velocity is the rate of change of displacement and acceleration is the rate of change of velocity. Impulse is a change in momentum
Sound level at distance of 15 m is given as 20 dB
so intensity at this distance is given as



now if we move closer to some some distance the sound level is now 50 dB
now the intensity is given as



now we know that



so now the distance from friend must be 47 cm
Answer:
0.82052 m
Explanation:
potential energy of spring = kinetic energy
=> 0.5kx^2 = 0.5mv^2
=> 

v= 3.11127 m/s
angle = 37°
thus height = distance×sin(37) = D×0.60182
Also,
m×g×h = 0.5×m×v^2
=> 2×9.8×D×0.60182 = 0.5×2×3.11127×3.11127
=> D = 0.82052 m