Answer:
0 N/C
Explanation:
Parameters given:
The distance between and
is
Electric field is given as
r = 15/2 = 7.5cm = 0.075m
The electric field at their midpoint due to is:
=
The electric field at the midpoint due to is:
=
The net electric field will be:
E = +
E = +
E = 0 N/C
Answer:
The correct option is;
d) Parallel to the plane
Explanation:
The forces acting on the box of mass, m are;
Weight of the box acting an angle, θ, equal to the inclination of the plane to the perpendicular of the plane
Weight of the box acting along the plane = m×g×sin(θ)
The force of friction along the plane = μ×m×g×cos(θ)
The total force acting downward along the plane , = m×g×sin(θ) + μ×m×g×cos(θ)
The Force needed to pull the box up along the plane F = The total force acting downward along the plane
F = m×g×sin(θ) + μ×m×g×cos(θ) = m×g×(sin(θ) + μ×cos(θ))
When the force, Fₐ is applied vertically, the force acting along the plane = Fₐ×cos(θ)
When the force is applied perpendicular, the force acting along the plane = Fₐ×sin(θ)
When the force is applied horizontally, the force acting along the plane = Fₐ×cos(θ)
When the force is applied parallel to the plane, the force acting along the plane = Fₐ
Therefore, since Fₐ > Fₐ×cos(θ) and Fₐ > Fₐ×sin(θ), for acute angles, we have that the least force is required when the force is acting parallel to the plane.
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
:
8.6 cm
Explanation:
Step 1:
In this we have to find the focal length of converging lens.
To find focal length we have,
where u = Object distance
v= Image distance
f = Focal length
Step 2:
(1/f) = 0.116
f = 1/0.116
f = 8.6 cm
Where,
Now, Converting gram to kg
1000g = 1kg
20g =
= 0.02 kg
According to the question
Putting these values
Potential Energy = mgh
Potential Energy = 0.02 × 10 × 2
Potential Energy = 0.2 × 2
Potential Energy =