Answer:
0.43 s
Explanation:
We have the following parameters:
Initial velocity, u = 7.4 m/s
Acceleration of gravity, g = 9.8 
Distance, s = 43 in + 10 ft = 1.092 m + 3.048 m = 4.14 m
Time, t = ?
Using the equation of motion 
, we have
Using the quadratic formula 
where a = 4.9, b = 7.4 and c = - 4.14, and solving for the positive value of t only, we have
s
First we need to find the acceleration of the skier on the rough patch of snow.
We are only concerned with the horizontal direction, since the skier is moving in this direction, so we can neglect forces that do not act in this direction. So we have only one horizontal force acting on the skier: the frictional force,
. For Newton's second law, the resultant of the forces acting on the skier must be equal to ma (mass per acceleration), so we can write:
Where the negative sign is due to the fact the friction is directed against the motion of the skier.
Simplifying and solving, we find the value of the acceleration:
Now we can use the following relationship to find the distance covered by the skier before stopping, S:
where
is the final speed of the skier and
is the initial speed. Substituting numbers, we find:
Answer:
The Michelson-Morley was designed to detect the motion of the earth through the ether.
No such relation was found and the speed of light is assumed to be the same in all reference frames.
