No force contributes to density, the density is a physical quantity that is defined as being
the raport between the mass of the object and its volume. However if you want to measure the density of an object you might want to determine its gravity force (weight)
from which knowing the gravitational acceleratin you can find its mass
where
is given in Newtons and
is given in
Answer:
Explanation:
The volume of contaminated water
= cross sectional area x height of water level
3.14 x 9 x 9 x 7.5 ft³
= 1907.55 ft³
mass = density x volume
= 1907.55 x 63.5 lbs
m = 121129.425 lbs
This mass has to be raised to the height of 8 ft before evacuation .
There is a rise of centre of mass of
8 - 7.5/2 ft
h = 4.25 ft
Energy required
= mgh
= 121129.425 x 32 x 4.25
= 16473601.8 unit.
Volume = mass / density
Volume = 20 / 7.87
Volume = 2.54 (2 s.f)
Explanation:
It is given that,
Mass of person, m = 70 kg
Radius of merry go round, r = 2.9 m
The moment of inertia, 
Initial angular velocity of the platform, 
Part A,
Let 
is the angular velocity when the person reaches the edge. We need to find it. It can be calculated using the conservation of angular momentum as :
Here, 
Solving the above equation, we get the value as :
Part B,
The initial rotational kinetic energy is given by :
The final rotational kinetic energy is given by :
Hence, this is the required solution.
