Answer:
The speed of the skier after moving 100 m up the slope are of V= 25.23 m/s.
Explanation:
F= 280 N
m= 80 kg
α= 12º
μ= 0.15
d= 100m
g= 9,8 m/s²
N= m*g*sin(α)
N= 163 Newtons
Fr= μ * N
Fr= 24.45 Newtons
∑F= m*a
a= (280N - 24.5N) / 80kg
a= 3.19 m/s²
d= a * t² / 2
t=√(2*d/a)
t= 7.91 sec
V= a* t
V= 3.19 m/s² * 7.91 s
V= 25.23 m/s
Answer:

Explanation:
= Angular speed
= Distance of Mary = 11.5 ft
= Distance of Alex = 6 ft
Ratio of centripetal acceleration is given by

Mary's centripetal acceleration is 1.92 times the centripetal acceleration of Alex
Answer:
e. Both the acceleration and net force on the car point inward.
Explanation:
If no net force acts on the car, the car must drive in a straight line, at constant speed.
As the acceleration is defined as the rate of change of the velocity vector, this means that it can produce either a change in the magnitude of the velocity (the speed) or in the direction.
In order to the car can follow a circular trajectory, it must be subjected to an acceleration, that must go inward, trying to take the car towards the center of the circle.
The net force that causes this acceleration, aims inward, and is called the centripetal force.
It is not a different type of force, it can be a friction force, a tension force, a normal force, etc., as needed.
By law of refraction we know that image position and object positions are related to each other by following relation

here we know that



now by above formula


so apparent depth of the bottom is seen by the observer as h = 3.39 cm