Answer:
Some lenses are used to focus light to a pre-defined point based on the amount of curvature of their surfaces.
In a piano design convex, some surfaces are flat while others has positive lenses (biconvex)
Explanation:
Solution
These lenses are applied to pay attention to light in a point pre-defined based on the amount of curvature of their surfaces.
For that of a plano-convex design, one surface has a positive curve and for biconvex lenses, both surfaces are positively curved while the other remains flat.
when used practically, plano-convex lenses are most commonly used where the object being imaged is far apart from lens.
Answer:
a

b

Explanation:
From the question we are told that
The mass of the rock is 
The length of the small object from the rock is 
The length of the small object from the branch 
An image representing this lever set-up is shown on the first uploaded image
Here the small object acts as a fulcrum
The force exerted by the weight of the rock is mathematically evaluated as

substituting values


So at equilibrium the sum of the moment about the fulcrum is mathematically represented as

Here
is very small so
and 
Hence

=> 
substituting values


The mechanical advantage is mathematically evaluated as

substituting values


I believe it would be Tendonitis
Answer with Explanation:
We are given that
Initial velocity,u=4.5 m/s
Time=t =0.5 s
Final velocity=v=0m/s
We have to find the deceleration and estimate the force exerted by wall on you.
We know that
Acceleration=
Using the formula
Acceleration=
deceleration=a=
We know that
Force =ma
Using the formula and suppose mass of my body=m=40 kg
The force exerted by wall on you
Force=