Math Is Fun Forum

sk

Member

Registered: 2006-08-04

Posts: 19

Help me with this

A ship develops a leak 12 km from the shore. Despite the leak, the ship is able to move towards the shore at a speed of 8 km/hr. However, the ship can stay afloat only for 20 minutes. If a rescue vessel were to leave from the shore towards the ship, and it takes 4 minutes to evacuate the crew and passengers of the ship, what should be the minimum speed of the rescue vessel in order to be able to successfully rescue the people aboard the ship?

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

Re: Help me with this

displacement of ship from shore with respect to time is 12-8t
displacement of rescue vessel from shore with respect to time is vt

the maximum time the process of getting to the ship can take is 20-4 minutes = 16minutes
in 16 minutes -> 16/60 -> 4/15hr, the ships displacement from shore will be 12-8*4/15 = 9+13/15

vt = 9 + 13/15
v = (9+13/15)/(4/15) = (148/15)/(4/15) = 148/4 = 37km/hr

Last edited by luca-deltodesco (2007-07-09 18:55:03)

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