The image mentioned is in the attachment
Answer: a) P = 2450 Pa;
b) P = 2940 Pa;
c) F = 4.9 N
Explanation:
a) Pressure is a force applied to a surface of an object or fluid per unit area.
The image shows a block applying pressure on the large side of the piston. The force applied is due to gravitation, so:
P = 
P = 
P = 
P = 2450 Pa
The pressure generated by the block is P = 2450 Pa.
b) A static liquid can also exert pressure and can be calculated as:
ρ.g.h
where
ρ is the density of the fluid
h is the depth of the fluid
g is acceleration of gravity
600.9.8.0.5
2940 Pa
The pressure in the fluid at 50 cm deep is
2940 Pa.
c) For the system to be in equilibrium both pressures, pressure on the left side and pressure on the right side, have to be the same:

= 
F = 
Adjusting the units,
= 0.002 m².
F = 
F = 4.9 N
The force necessary to be equilibrium is F = 4.9 N.
Answer:

Explanation:
Considering an object that moving about in a circular path, the equation for such centripetal force can be computed as:

The model for the person can be seen in the diagram attached below.
So, along the horizontal axis, the net force that is exerted on the person is:

Dividing both sides by "m"; we have :

Making "v" the subject of the formula: we have:


So, when
= 0; the velocity is maximum
∴




Hence; the maximum walking speed for the person is 