Question

please solve this question ..........please......​

Answer 1

Answer:

18. a. t=2

19. U²G

20. (d)

21. (c)

22. b)

Answer 2

Let the particles A and B collide at time t. For their collision, the position vectors of both particles should be same at time t, i.e.

r1→+v1→t=r2→+v2→t

r1→−r2→=v2→t−v1→t

=(v2→−v1→)t...(i)

Also, |r1→−r2→|=|v1→−v1→|t or t=|r1→−r2→||v2→−v1→|

Substituting this value of t in eqn. (i), we get

r1→−r2→=(v2→−v1→)|r1→−r2→||v2→−v1→|

or r1→−r2→|r1→−r2→|=(v2→−v1→)|v2→−v1→|