Answer: 21965.517 Pa
Explanation:
Pressure
is the force
exerted by a gas, a liquid or a solid on a surface (or area)
, its unit is Pascal
which is equal to
and its formula is:
(1)
In this case we have the surface of a sole of a tennis shoe:
(2)
And the mass
of the person who wears it:
On the other hand, we know the weight is the force
the Earth exerts on people and objects due gravity
:
(3)
Substituting (2) and (3) in (1):
(4)
Finally:
This is the pressure the shoe exert on the ground
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> 
Explanation:
Average speed = distance / time
|v| = (7 km + 2 km) / (2 hr + 1 hr)
|v| = 3 km/hr
Average velocity = displacement / time
v = (7 km east + 2 km east) / (2 hr + 1 hr)
v = 3 km/hr east