In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction
Answer:
Approximately
(assuming that the acceleration due to gravity is
.)
Explanation:
Let
denote the first piston's contact area with the fluid. Let
denote the second piston's contact area with the fluid.
Similarly, let
and
denote the size of the force on the two pistons. Since the person is placing all her weight on the first piston:
.
Since both pistons fit into cylinders, the two contact surfaces must be circles. Keep in mind that the area of a square is equal to
times its radius, squared:
.
.
By Pascal's Law, the pressure on the two pistons should be the same. Pressure is the size of normal force per unit area:
.
For the pressures on the two pistons to match:
.
,
, and
have all been found. The question is asking for
. Rearrange this equation to obtain:
.
Evaluate this expression to obtain the value of
, which represents the force on the piston with the larger diameter:
.
Contact is 'touching'. If a person 'touches' something skins cells, sweat and DNA are left behind. This confirms that a person was present.
The combination of all of the forces acting on object is net force.