Answer:
v = 4.58 m/s
Explanation:
In order to calculate the speed of the skier when she gets the bottom of the hill, you have to calculate the speed of the skier when she crosses the rough patch.
To calculate the velocity at the final of the rough patch you take into account that the work done by the friction surface is equal to the change in the kinetic energy of the skier:
(1)
Where the minus sign means that the work is against the motion of the skier.
Wf: friction force
m: mass of the skier = 65.0kg
N: normal force = mg
g: gravitational acceleration = 9.8m/s^2
d: distance of the rough patch = 4.00m
v: speed at the end of the rough patch = ?
vo: initial speed of the skier = 6.85m/s
μk: coefficient of kinetic friction = 0.330
You replace the expression for the normal force in the equation (1), and solve for v:

Then, the speed fot he skier at the bottom of the hill is 4.58m/s
Answer: 6.175 km
Explanation:
from the question, we have the following
velocity of the automobile = 95 km/g
velocity of the train = 75 km/h
length of the train = 1.30 km
since the automobile and the train are moving in the same direction, we need to find the velocity of the car relative to the train which will be their difference in speed = 95 - 75 = 20 km/h
we need to find the time it takes the automobile to overtake the train using the formula time = distance / speed , with the distance being the length of the train.
time (t) = 1.3 / 20
= 0.065 hour
now we can find the distance traveled by the automobile using the the time taken for it to overtake the train and the speed of the automobile.
therefore, distance = speed x time
distance = 95 x 0.065 =6.175 km
assuming north-south along the Y-axis and east-west along the X-axis
X = total X-displacement
from the graph , total displacement along X-direction is given as
X = 0 - 20 + 60 Cos45 + 0
X = 42.42 - 20
X = 22.42 m
Y = total Y- displacement
from the graph , total displacement along Y-direction is given as
Y = 40 + 0 + 60 Sin45 + 50
Y = 90 + 42.42
Y = 132.42 m
magnitude of the net displacement vector using Pythagorean theorem is given as
magnitude : Sqrt(X² + Y²) = Sqrt(22.42² + 132.42²) = 134.31 m
Direction : tan⁻¹(Y/X) = tan⁻¹(132.42/22.42) = 80.4 deg north of east