Answer:
electric current is derived unit.
Explanation:
According to the definition of electric current, it appears to be a derived quantity. Charge on the other hand seems more fundamental than electric current.
So, a concave mirror is a mirror that goes inward, thus, making a convex mirror have an outward curvature. Ex: A convex mirror is used at the front of a bus.
Answer: 115.38N
Explanation:
Firstly, let's determine the constant.
Hooke's law was discovered by Robert Hooke in 1660.
Using hooke's law which states that provided the elastic limit of an elastic material is not exceeded, the force is equal to the extension applied provided all factors are kept constant.
Hooke's Law is a principle of physics that states that the force which is needed to extend or compress a spring by some distance is proportional to that distance
Therefore,
Force=kx
K= F/x
Where Force= 75m
x= 0.065m
K= 75/0.065m
K= 1153. 846N
We can use the constant to find the force when the distance that is stretched(x) is known.
Here
Force=kx
F= 1153.846 × 0.10
F= 115.38N
The force required to stretch it by this amount is 115.38N.
As we know that work done is defined as product of force and displacement in the direction of applied force
so we can say it is
or we can say
so we will have following options
A)Pushing against a locked door
There is no work done in above case as there will be no displacement in that case so work done is ZERO
B) Carrying a box down a corridor
While we move done and carrying a box then work done by gravity on the box while our work done is negative work.
C) Pulling a trailer up a hill
In above case our work done to pull a box up a hill is positive work as we need to work against gravity
D) Suspending a heavy weight with a strong chain
During suspension there is no displacement so there will be no work done in above case
so correct answer will be
<em>Pulling a trailer up a hill</em>
