4.) We are told that ball A is travelling from right to left, which we will refer to as a positive direction, making the initial velocity of ball A, +3 m/s. If ball B is travelling in the opposite direction to A, it will be travelling at -3 m/s. The final velocity of A is +2 m/s. Using the elastic collision equation, which uses the conservation of linear momentum, we can solve for the final velocity of B.
MaVai + MbVbi = MaVaf + MbVbf
Ma = 10 kg and Mb = 5 kg are the masses of balls A and B.
Vai = +3 m/s and Vbi = -3 m/s are the initial velocities.
Vaf = +2 m/s and Vbf = ? are the final velocities.
(10)(3) + (5)(-3) = (10)(2) + 5Vbf
30 - 15 = 20 + 5Vbf
15 = 20 + 5Vbf
-5 = 5 Vbf
Vbf = -1 m/s
The final velocity of ball B is -1 m/s.
5.) We are now told that Ma = Mb, but Vai = 2Vbi
We can use another formula to look at this mathematically.
Vaf = [(Ma - Mb)/(Ma + Mb)]Vai + [(2Mb/(Ma + Mb)]Vbi
Since Ma = Mb we can simplify this formula.
Vaf = [(0)/2Ma]Vai + [2Ma/2Ma]Vbi
Vaf = Vbi
Vbf = [(2Ma/(Ma + Mb)]Vai + [(Ma - Mb)/(Ma + Mb)]Vbi
Vbf = [2Mb/2Mb]Vai + [(0)/2Mb]Vbi
Vbf = Vai
Vaf = Vbi
Vbf = 2Vbi
If the initial velocity of A is twice the initial velocity of B, then the final velocity of A will be equal to the initial velocity of B.
If the initial velocity of A is twice the initial velocity of B, then the final velocity of B will be twice the initial velocity of B.
The solar system is considered a natural system because it was made and controlled by natural forces, meaning, it was never influenced with human creations. It is considered as one of the products of the phenomenon of the physical world. Hope this answer helps you.
There are 7 days in a week so 14/7 is 2 so 2 weeks!
