I attached a Diagram for this problem.
We star considering the system is in equlibrium, so
Fm makes 
with vertical
Fm makes 70 with vertical
Applying summatory in X we have,
We know that W is equal to
Substituting,
<em>For the second part we know that the reaction force Fj on deltoid Muscle is equal to Fm, We can assume also that</em> 
Answer:
1047 miles
Explanation:
The radius of the Earth is
(miles)
So its circumference, which is the total length of the equator, is given by
Now we know that the Earth rotates once every 24 hours. So the distance through which the equator moves in one hour is equal to its total length divided by the number of hours, 24:
To calculate instantaneous speed, we need to divide part of the total distance traveled by time. However, we don't want to use the distance of the entire trip, because that will give us average speed.
