The position vectors of two balls are given by
r1→ = 2(m)i^+7(m)j^
r2→ = −2(m)i^+4(m)j^
What is the distance between the two balls?
4 m
4.5 m
5 m
3 m
r2→ = −2mi^+4mj^
∴ r1→−r2→ = [2−(−2)]i^+(7−4)j^
∴|r1→ −r2→| = 42+(3)2 = 52 = 5 m