Calculating Rotational Moment of Lever & Mass

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In summary, the conversation is about finding the mass needed on one side of a pivot point to create a balance with a known resistance on the other side. The pivot point has a lever with 95 pounds of resistance at 90 degrees, while the other side has a mass at the end of a 15.25-inch lever with an angle of intersection of 12 degrees and a vertical distance of 5 inches. The calculations involve using the sine function and possibly adding in the 5-inch length, but the sketch provided does not match the given description.
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Ranger Mike
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I need your help. I have a pivot point. On one side there is 95 pounds of resistance at 90 degrees to the lever. The lever is 18 inch long. on the other side of the pivot point I have a mass at the end of a 15.25” long lever. This mass wants to rotate clockwise about the pivot. The angle of intersection to the pivot is 12 degrees. The distance vertically between these two points is 5 inches.
Doing the math 95 x 18 x 1 ( sine of 90 degrees) = 1710
If I want the mass on the other side of the equation..I am getting confused by the 5 inch length. I know .208 is sine of 12 degrees.
Do I add in the 5 inch to the calculation...??
 

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Your sketch does not match the description.

i.e. as drawn, assuming gravity acts "down", the mass wants to move anticlockwise.
You have the 5" line vertical (OK) - which makes it the opposite side of a rt-angled triangle with a hypotenuse of 15.25" and an angle of 12deg. But this is not consistent since 15.25"sin(12)=3.17" i.e. there is no way the angle drawn is 12deg and the vertical distance is 5".
 
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1. What is rotational moment of a lever and mass?

The rotational moment, also known as torque, of a lever and mass is the measure of the force that causes an object to rotate around a fixed point. It is calculated by multiplying the force applied to the lever by the distance from the pivot point.

2. How do you calculate the rotational moment of a lever and mass?

The rotational moment can be calculated by using the formula: torque = force x distance. The force should be measured in newtons and the distance in meters.

3. What is the unit of measurement for rotational moment?

The unit of measurement for rotational moment is Newton-meters (Nm) in the SI system. In the imperial system, it is measured in foot-pounds (ft-lb).

4. How does the mass of an object affect its rotational moment?

The mass of an object affects its rotational moment in two ways. Firstly, the greater the mass, the greater the force needed to cause rotation. Secondly, the distribution of the mass around the pivot point also plays a role in the rotational moment.

5. How is the pivot point chosen when calculating the rotational moment?

The pivot point, also known as the fulcrum, is the point around which the object rotates. It is generally chosen as the point of support for the lever. In some cases, the pivot point may be chosen strategically to make calculations easier.

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