Thursday

December 18, 2014

December 18, 2014

Posted by **jess** on Friday, June 25, 2010 at 10:33pm.

I know there is going to be 2 unknowns and x+7 is the new distance from the pivot to the c of mass of the meter stick, but I am so lost as to how to put this together, please help. thanks

- physics -
**MathMate**, Friday, June 25, 2010 at 10:45pmFirst balance

...150................M.........200......

...................^.....................

....10............50..x..........75......

second balance

...150................M.........200......

..............^...........................

....10.......43.......x..........75......

M=mass

x=distance from left (=graduation)

- physics -
**jess**, Friday, June 25, 2010 at 10:52pmdiagrams help, i had these almost exactly drawn out, but i do not know how to create the equations to solve for the unknowns. thanks

- physics -
**MathMate**, Friday, June 25, 2010 at 10:56pmFirst balance

...150................M.........200......

...................^.....................

....10.........50.....x..........75......

second balance

...200................M.........150......

..............^...........................

....10....43..........x..........75......

third line: distance from left

M=mass

x=distance from left (=graduation)

For first balance, take moments about pivot point (=50), clockwise = positive, counterwise = negative:

-150(50-10)+M(x-50)+200(75-50)=0

For second balance:

-200(43-10)+M(x-43)+150(75-43)=0

Solve for M and Mx.

Divide Mx by M to get x.

I get

M=800/7=114.3

x=58.75 cm from zero.

**Answer this Question**

**Related Questions**

Physics 1 - A meter stick has a mass of 200g and its center of gravity is at the...

Physics - In lab, a meter stick has its center of gravity at the 45.5 mark. The ...

physics( i have no idea how to go about gettign th - a uniform meter stick of ...

physics - A meter stick balances horizontally on a knife-edge at the 50.0 cm ...

Physics - A meter stick balances horizontally on a knife-edge at the 50.0 cm ...

physic - a uniform meter stick of mass 100g is pivoted about the 30 cm mark. a ...

physics - A particle of mass 0.350 kg is attached to the 100-cm mark of a meter ...

physics - if the fulcrum of a .15 kg meter stick was placed at 25 cm and a 300 ...

physics - if the fulcrum of a .15 kg meter stick was placed at 25 cm and a 300 g...

Physics* - A meter stick is found to balance at the 49.7-cm mark when placed on ...