- #1

fiziks09

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## Homework Statement

A square uniform raft, 18m by 18m of mass 6200kg is used as a ferry boat. if three cars each of mass 1350 kg occupy the NE, SE, and SW corners, determine the Centre of mass of the loaded ferryboat relative to the centre of the raft

## Homework Equations

Center of mass (CM) = [tex]\sum mixi/M[/tex]

where M = m1 + m2...mn

## The Attempt at a Solution

The centre of mass i think, is going to be two-dimensional i.e x-axis and y-axis

So i drew my co-ordinate system and came up with the following

CM(x-axis) = 1350(18) + 1350(18) +1350(-18)/3(1350)+6200 = 2.3i

The -18 is for the SW car where x is negative.

CM(y-axis) = 1350(18) + 1350(-18) +1350(-18)/3(1350) + 6200= -2.3j

i have two -18's coz for the SW and NW where y is negative..

I used 18 as the distance for all three cars since the raft is 18m by 18m. But my solution is wrong. Please any help will be very appreciated. Thanks