Answer:
ρ = 830.32 kg/m³
Explanation:
Given that
Oil head = 12.2 m
h= 12.2 m
Pressure P = 1.013 x 10⁵ Pa
Lets take density of the liquid =ρ
The pressure due to liquid P given as
P = ρ g h
Now by putting the all values in the above equation
1.013 x 10⁵ Pa = ρ x 10 x 12.2 ( take g =10 m/s²)
ρ = 830.32 kg/m³
Therefore the density of oil is 830.32 kg/m³
Because: Some of the work done by the machine is used to overcome the friction created by the use of the machine. ... Work output can never be greater than work input. Machines allow force to be applied over a greater distance, which means that less force will be needed for the same amount of work.
The net force = sum of all forces acting on the body
If we take left side as -ve and right side as +ve,
then,
The net force here would be equal to,
10N + (- 3N)
= 7N.
Therefore, a net force of +7N ( + indicates it's moving towards right) is acting on the book of mass 2kg.
C is the answer to your question.