Reduce friction because friction just makes things harder
...the potential energy that you build while going up the hill on the roller coaster could be let go as kinetic energy -- the energy of motion that takes you down the hill of the roller coaster.
Explanation:
Coefficient of kinetic friction is the resistive force that opposes the motion of a body as it moves and is in contact with another body.
It is found by dividing the frictional force by the normal force.
- Friction is a force that opposes motion.
- Static friction is for bodies that are not in motion
- Kinetic friction is for moving bodies.
We will apply the conservation of linear momentum to answer this question.
Whenever there is an interaction between any number of objects, the total momentum before is the same as the total momentum after. For simplicity's sake we mostly use this equation to keep track of the momenta of two objects before and after a collision:
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'
Note that v₁ and v₁' is the velocity of m₁ before and after the collision.
Let's choose m₁ and v₁ to represent the bullet's mass and velocity.
m₂ and v₂ represents the wood block's mass and velocity.
The bullet and wood will stick together after the collision, so their final velocities will be the same. v₁' = v₂'. We can simplify the equation by replacing these terms with a single term v'
m₁v₁ + m₂v₂ = m₁v' + m₂v'
m₁v₁ + m₂v₂ = (m₁+m₂)v'
Let's assume the wood block is initially at rest, so v₂ is 0. We can use this to further simplify the equation.
m₁v₁ = (m₁+m₂)v'
Here are the given values:
m₁ = 0.005kg
v₁ = 500m/s
m₂ = 5kg
Plug in the values and solve for v'
0.005×500 = (0.005+5)v'
v' = 0.4995m/s
v' ≅ 0.5m/s
Law of universal gravitation:
F = GMm/r²
F = gravitational force, G = gravitational constant, M & m = masses of the objects, r = distance between the objects
F is proportional to both M and m:
F ∝ M, F ∝ m
F is proportional to the inverse square of r:
F ∝ 1/r²
Calculate the scaling factor of F due to the change in M:
k₁ = 2M/M = 2
Calculate the scaling factor of F due to the change in m:
k₂ = 2m/m = 2
Calculate the scaling factor of F due to the change in r:
k₃ = 1/(4r/r)² = 1/16
Multiply the original force F by the scaling factors to obtain the new force:
Fk₁k₂k₃
= F(2)(2)(1/16)
= F/4
