<span>Taking into account the information above, we know the average mass of the bucket of water may be m=20-5/2=17.5kg. As the bucket of water is pulled at a "constant velocity" the work required to raise the bucket to the platform transformed into the potential energy of the bucket of water. That is why it should be W=mgh=17.5*9.8*40=6860J</span>
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:
B) The wavelength of both transverse and longitudinal waves is measured parallel to the direction of the travel of the wave
Use your notes or look for the answer on your book