Answer:
v = 9.04 m / s
Explanation:
For this exercise we can use the relation that the work of the non-conservative force (friction) is equal to the variation of the mechanical energy of the system.
W = Em_f - Em₀ (1)
Starting point. Lower slope
Em₀ = K = ½ m v²
highest point. Where is the skier at a height h
Em_f = U = m g h
The work of rubbing
W = -fr x
the negative sign is because the friction force opposes the movement.
Let's set a reference system where the x axis is parallel to the slope and the y axis is perpendicular
let's use trigonometry to break down the weight
cos θ = W_y / W
sin θ = Wₓ / W
W_y = W cos θ
Wₓ = W sin θ
Y axis
N - Wₓ = 0
N = mg sin θ
X axis
fr = m a
the friction force has the expression
fr = μ N
fr = μ mg sin θ
we look for the job
W = - μ mg sin θ x
where x is the distance along the slope
we substitute in 1
-μ mg sin θ x = mg h - ½ m v²
let's use trigonometry to find the distance x
tan 30 = h / x
x = h / tan 30
we substitute
-
= m gh - ½ m v²
we use
tan 30 = sin30 / cos30
v² = 2g h + 2 μ g h cos 30
v = 
let's calculate
v = 
v = 9.04 m / s
Answer:
1. 2.5km
2. 4.8m
3. 0.075 litre
4. 65000mg
5. 5600g
6. 0.5m
7. 63mm
Explanation:
1. 1000m in 1 km so divide by 1000
2. 100cm in m so divide by 100
3. 1000ml in 1l so divide by 1000
4. multiply the mass value by 1000
5.multiply the mass value by 1000
6. divide the length value by 100
7. multiply the length value by 10
hope this helps
Rotational speed would increase...
v = omega . r
which means it's directly proportional to radius...
It's a measure of the acceleration