False because opposites attract. :)
Velocity of swimmer across river = 1.30 m/s
Distance arrived downstream = 48 m
Width of river = 64 m
Time taken to cross river = 
= 
Speed of river current = 
= 
So, the river is flowing at a speed 0.975 m/s.
Answer: My initial velocity is 5 m/s.
Explanation:
In this case, momentum can be conserved.
initial momentum = final momentum
Since both the bodies come to rest after collision,
Final momentum = 0
Let my velocity be v, and mass, m1 = 60 kg
Friend's mass, m2 = 100 kg
Friend's velocity, v2 = 3 m/s
Intial momentum = m1v + m2v2
= 60v + 300
Conserving momentum,
60v + 300 = 0
v= -5 m/s
( Negative sign indicates that me and my friend are moving in opposite directions that is towards each other)
<span>You could easily define it this way. This would be valid. But for most of history it was unclear when a baby was conceived, so it would be silly for someone to say their baby was 9 months old when it was actually born at only 8.5 months. Days of conception similarly would not be a good substitute for birthdays because no one would know them. Then in general it was much easier to mark someone's age as when they came into the world as an independent being, and this tradition is far too entrenched (and simple and easy to handle and universal for people in poor countries etc) to think we would at all gain from now finding exactly the date of conception and counting age from that point.</span>
