A square uniform raft, 17.9m by 17.9m, of mass 6254kg, is used as a ferryboat. If three cars, each of mass 1244kg, occupy the NE, SE, and SW corners, determine the CM of the loaded ferryboat. Use east as the positive x-axis, north as the positive y-axis and the centre of the raft as the origin.

Question

anonymous · Answer

well you could turn your ferry boat into the cartesian plane and say the cars are at point (9,9) for ne,  (9,-9) for se, and (-9,-9) for sw. and then use the center of mass formula.

anonymous · Answer

Soo.. I would use (8.95,8.95) for Ne (8.95, -8.95) for se, and (-8.95,-8.95) for sw?

anonymous · Answer

wow i must be seeing things i could thought that said 18mx18m but yes thats what i would do

anonymous · Answer

right? sooo, what is the v $$CM = (m_1v_1 + m_2v_2 +m_3v_3 + m_4v_4) \div (m_1 +m_2 +m_3 +m_4)$$

anonymous · Answer

looks right to be

anonymous · Answer

I get that v is the (8.95, 8.95) stuff.. but how do you work that out with the formula

anonymous · Answer

$$X_{cm}=\frac{(m_1)(x_1)}{m}$$

anonymous · Answer

us that for all the x's and then do it for all the y's

anonymous · Answer

the m on the bottom, thats total mass I'm guessing? and then what do i do?

anonymous · Answer

well you got to do total mass on the bottom and do m1x1+m2x2... for the top

anonymous · Answer

ok thanks

anonymous · Answer

remember you also have to do that for the y components