Answer:
+5.7 m/s
Explanation:
According to the law of conservation of momentum is that the momentum before the collision is equal to the momentum after the collision. In an equation form it would look like this:
M₁V₁+M₂V₂ = M₁V₁'+M₂V₂'
Where:
M₁ = mass of object 1 (kg)
V₁ = velocity of object 1 before the collision (m/s)
V₁' = Final velocity of object 1 after the collision (m/s)
M₂ = mass of object 2 (kg)
V₂ = velocity of object 2 before the collision (m/s)
V₂' = Final velocity of object 2 after the collision (m/s)
According to your problem you have the following given:
M₁ = 5 g = 0.005kg
V₁ = 3 m/s
V₁' = -5m/s (It bounced off so it is going the other direction)
M₂ = 6g = 0.006kg
V₂ = -1 m/s (It is coming from the opposite direction of the 3-ball)
V₂' = ?
So we plug in what we know and solve for what we don't know.
Answer:
the number of grains in the ball is 274,848
Explanation:
Given that;
diameter = 0.5 mm
so radius r = 0.25 mm
first we determine the volume of the ball using the following equation;
V = 4/3×πr³
we substitute
V = 4/3×π(0.25)³
V = 0.06544 mm³
Now form table 1.1 "Grain sizes" a metal with grain size number of 12 has about 4,200,000 grains/mm³
so;
Number of grains N = 0.06544 × 4,200,000
N = 274,848 grains
Therefore, the number of grains in the ball is 274,848
