Answer: the waves travel in an horizontal direction while the strings vibrate in a vertical direction.
In order to find the final velocity of the skier and the trash can lid, we may apply the principle of conservation of momentum, which states that the total momentum of a system remains constant. Mathematically, in this case:
m₁v₁ + m₂v₂ = m₃v₃
Where m₃ and v₃ are the combined mass and velocity.
75*3 + 10*2 = (75 + 10)*v₃
v₃ = 2.88 m/s
The final velocity is 2.88 m/s
when the two waves interfere with eachother to make a dark spot the periodic difference of the two waves is π . the wave length for 2π is 600nm
. ie. for π difference it is 300nm