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help with mechanics/vectors? watch
- Thread Starter
Last edited by username3786456; 17-02-2018 at 13:33.
- 14-02-2018 13:08
- 15-02-2018 12:14
Hi! I've moved this into the Maths forum for you - hopefully someone will be able to help you out here
(Original post by an1megod)
- 15-02-2018 12:19
A river flows at 0.3m/s. Peter and Mary, who can each swim at 0.5m/s in still water, wish to cross the river. The River is 20 metres wide.
a) Peter aims straight across the river, and is carried downstream by the current.
i) how long does he take to reach the other side?
ii) work out his actual speed of travel
Mary swims to the closest point on the opposite bank.
i) in which direction does she aim?
ii) work out her actual speed of travel
iii) how long does it take her to reach the other side?
I don't understand what I have to do with this question at all. Just need some pointers.
for Peter the two short sides will be his still water speed and the current speed
for Mary the long side will be her still water speed and one of the short sides will be the current speed.