Answer:
μ = tan θ
Explanation:
For this exercise let's use the translational equilibrium condition.
Let's set a datum with the x axis parallel to the plane and the y axis perpendicular to the plane.
Let's break down the weight of the block
sin θ = Wₓ / W
cos θ = W_y / W
Wₓ = W sin θ
W_y = W cos θ
The acrobat is vertically so his weight decomposition is
sin θ = = wₐₓ / wₐ
cos θ = wₐ_y / wₐ
wₐₓ = wₐ sin θ
wₐ_y = wₐ cos θ
let's write the equilibrium equations
Y axis
N- W_y - wₐ_y = 0
N = W cos θ + wₐ cos θ
X axis
Wₓ + wₐ_x - fr = 0
fr = W sin θ + wₐ sin θ
the friction force has the formula
fr = μ N
fr = μ (W cos θ + wₐ cos θ)
we substitute
μ (Mg cos θ + mg cos θ) = Mgsin θ + mg sin θ
μ = 
μ = tan θ
this is the minimum value of the coefficient of static friction for which the system is in equilibrium.
Vs - velocity on beginning
ve - velocity on ending. You've got:
So he needed 4 second.
Answer:
The main difference in these two movements is that the first is a pure swing movement and the followed form a wave travels from the beach
Explanation:
The movement in the two parts is very different, when the surf zone has passed it is in a deeper part of the water where the seabed does not rise much, therefore due to the movement of the waves there is an upward oscillatory movement and descending, in this movement there is no horizontal displacement.
When it is within the southern zone, there is a rapid rise of the sea floor, which generates a horizontal movement, having a traveling wave, therefore your movement is more complicated, you can have some oscillating movement on the axis and, but in addition to this you have a horizontal movement that reaches you towards the beach, forming a Traveling wave.
The main difference in these two movements is that the first is a pure swing movement and the followed form a wave travels from the beach
