Answer:
W= 4.4 J
Explanation
Elastic potential energy theory
If we have a spring of constant K to which a force F that produces a Δx deformation is applied, we apply Hooke's law:
F=K*x Formula (1): The force F applied to the spring is proportional to the deformation x of the spring.
As the force is variable to calculate the work we define an average force
Formula (2)
Ff: final force
Fi: initial force
The work done on the spring is :
W = Fa*Δx
Fa : average force
Δx : displacement
:Formula (3)
: final deformation
:initial deformation
Problem development
We calculate Ff and Fi , applying formula (1) :
We calculate average force applying formula (2):
We calculate the work done on the spring applying formula (3) : :
W= 11N*(0.7m-0.3m) = 11N*0.4m=4.4 N*m = 4.4 Joule = 4.4 J
Work done in stages
Work is the change of elastic potential energy (ΔEp)
W=ΔEp
ΔEp= Epf-Epi
Epf= final potential energy
Epi=initial potential energy
W=ΔEp= 5.39 J-0.99 J = 4.4J
:
A ball would be something that floats in warter
That is not true.
<span>According
to the law of conservation of mass, in a chemical reaction, the mass of
the reactants will always be the same as the mass of the products.</span>
Answer:
D. location
Explanation:
The gravitational field strength of Earth is determined by the virtue of the location within the Earth's gravitational field.
That's why all objects regardless of their mass, shape, and size free fall towards the Earth with an acceleration equal to the acceleration at that location in the absence of air resistance.
According to the gravitational force between two bodies, the force experienced by one body due to the other is independent of its own mass.
The gravitational force is given by equation
F = GMm/r²
If F is the force acting on the smaller body of mass 'm', then
F = ma
Therefore, the equation becomes,
ma = GMm/r²
a = GM/r²
The value of 'a' changes with respect to the value of 'r' such that if 'r' is the radius of the Earth, then the acceleration at a height 'h' from Earth surface is given by
a = GM/(r+h)²
Here it is clear that the acceleration at any point is only the inherent property of the Earth itself.
The gravitational field strength of Earth is determined by the virtue of the location within the Earth's gravitational field.
