While direction is not given, why not consider positive initial velocities for both objects? They can be collided at any angle, right? Aren't we supposed to calculate the sum of momentum in scalar form? m1*4 + m2*4 = m1*v1 + m2*v2 . Please explain.
Why is it that we can't just use the equation given on page 81 of the reference manual? "Knowing the value of e, the velocities after the impact are given as"
Hello, you can use that equation too and you should be able to get the same answer. However, I prefer using the equations I used here because it provides a good understanding of the equations. Thank you for sharing that 😊
@@Genieprep Thanks for the clarification! I kept getting -4 & 4 when using the other equation but realized I was using a positive velocity for both v1 and v2. Thank you for the awesome videos!
Oh that makes sense! Just be careful during your exam. Also, when you are not sure about a question, drawing always helps, so keep that in mind and Good luck with your studying!
The reason why +4 m/s and -4 m/s is not the correct answer, is that this would imply a perfectly elastic collision. We were given a coefficient of restitution of 0.5, rather than 1, so kinetic energy cannot be conserved.
