Question

Can you get v1 and v2 from delta Δv? (This is velocity, not speed. I just don't know how to get the sign.)

Answer 1

Explanation:

∆ refers to change in something(big or small).

Here it is used with velocity v, it means it is telling about the change in velocity.

Since velocity, being a vector, contains magnitude as well as direction, it cant be added directly.

For this, we uss vector addition.

Hence,

∆v = vector subtraction(or sum of vec. v2 and - v1).

In mathematical language, if anticlockwise angle between v1 and v2 is A.

∆v = vec. v2 - vec.v1

|∆v| = √|v1|² + |v2|² - 2|v1||v2|cosA, where |v1| and |v2| refers to the magnitude and direction is given by tangent(tan) of the angle made by v2 and ∆v = Asin(alpha)/(B + cos(alpha)).

Sign of any vector is given by the direction. If Asin(alpha)/(B + cos(alpha)) is -ve, ∆v is -ve. If it is +ve, ∆v is +ve.