Answer:
Explanation:
Given
mass of cannon and cart is 
Spring constant 
mass of Projectile 
Launch Velocity of cannon 
Launch angle 
As the External Force is zero therefore we can conserve momentum
Initially both Projectile and cannon is at rest
Conserving momentum in horizontal direction




i.e. cannon is moving in opposite direction of Projectile
Answer:
the floor absorb the water so the water is dry
Light will travel more slowly in a material with a higher index of refraction
Wind power is produced from the
wind turbines or sails that uses air flow to convert it into mechanical power.
It is an alternative to fossil fuel burning, it is all around, renewable,
clean, produces no greenhouse gases and uses little land. The advantages of
wind power have been greatly praised by many. However, it has disadvantages.
Wind power especially at farm is noisy and may spoil the view for their
neighboring people. Also the amount of electricity depends on the strength of
the wind. If no wind is around, no electricity is produced.
This is more to do with mathematics than physics,
but the square root of gravity on its own means nothing, its simply a acceleration due to gravity near the earth surface.
trying to find the speed of a falling object is a simple conservation of energy problem, then it has a meaning in that context.
however standing alone, it has no bearing to the real world. it is simply a mathematical term or construct we use in order to explain the real world. you see this all over the place in physics, you just have to get used to it.
for example:
mv^2=mhg
v^2=gh
v= SQRT(gh)
=SQRT(g)SQRT(h)
so SQRT means nothing on its own, simply a mathematical term to used to calculate the effects and actions in the real world.
i cant really compare it to Pi, sorry
but i hope you have a better understanding :)