A.is an example of decomposition reaction.
It’s C because just trust
Answer:
Explanation:
First of all, let's remind that:
- The kinetic energy of an object is given by 
, where m is the mass and v is the speed
- The momentum of an object is given by 
- The inertia of an object is proportional to its mass, so we can write 
, where k just indicates a constant of proportionality
In this problem, we have:
- 
(the two objects have same kinetic energy)
- 
(A has three times the momentum of B)
Re-writing both equation we have:
If we divide first equation by second one we get
And if we substitute it into the first equation we get
So, B has 9 times more mass than A, and so B has 9 times more inertia than A, and their ratio is:
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
