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tem_osu
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[SOLVED] Rigid Objects in Equilibrium & Center of Gravity
http://img149.imageshack.us/img149/8568/0968lr6sc4.gif
A lunch tray is being held in one hand, as the drawing illustrates. The mass of the tray itself is 0.220 kg, and its center of gravity is located at its geometrical center. On the tray is a 1.00 kg plate of food and a 0.350 kg cup of coffee. Obtain the force T exerted by the thumb and the force F exerted by the four fingers. Both forces act perpendicular to the tray, which is being held parallel to the ground.
T = ___N (downward)
F = ___N (upward)
Torque = force * distance
Mug 0.350*9.8* 0.300= 1.029 Nm
Plate 1.00*9.8*0.140= 1.372 Nm
Tray 0.220*9.8*0.100= 0.2156 Nm
Total Clockwise torque = 2.6166 Nm
2.6166 = 0.04T
T = 65.415 N - wrong answer
And I have no idea how to solve for F. Please help me.
Homework Statement
http://img149.imageshack.us/img149/8568/0968lr6sc4.gif
A lunch tray is being held in one hand, as the drawing illustrates. The mass of the tray itself is 0.220 kg, and its center of gravity is located at its geometrical center. On the tray is a 1.00 kg plate of food and a 0.350 kg cup of coffee. Obtain the force T exerted by the thumb and the force F exerted by the four fingers. Both forces act perpendicular to the tray, which is being held parallel to the ground.
T = ___N (downward)
F = ___N (upward)
Homework Equations
Torque = force * distance
The Attempt at a Solution
Mug 0.350*9.8* 0.300= 1.029 Nm
Plate 1.00*9.8*0.140= 1.372 Nm
Tray 0.220*9.8*0.100= 0.2156 Nm
Total Clockwise torque = 2.6166 Nm
2.6166 = 0.04T
T = 65.415 N - wrong answer
And I have no idea how to solve for F. Please help me.
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