A uniform metre rule balances on a knife edge at 60cm mark when weight of 20n is suspended at one end.calculate the weight of the metre rule.
well the center of mass of the ruler is at 50
so the weight must be at a point above 60 like 100
w *(60-50) = 20 (100-60)
10 w = 20*40
w = 2*40 = 80 N
A uniform metre rule balances on a knife edge at the 60 cm mark when a weight of 20N is suspended at one end. calculate the weight of the metre rule.
To calculate the weight of the meter rule, we need to consider the principle of moments. The principle of moments states that for an object to be in equilibrium, the sum of the clockwise moments must be equal to the sum of the anticlockwise moments.
In this case, the meter rule is balanced on a knife edge at the 60 cm mark, and a weight of 20 N is suspended at one end. Let's assume that the weight of the meter rule is W.
Since the meter rule is balanced, the clockwise moment produced by the suspended weight of 20 N is equal to the anticlockwise moment produced by the weight of the meter rule.
The equation can be set up as follows:
20 N x distance of weight from the pivot = W x distance of meter rule weight from the pivot
Since the meter rule balances at the 60 cm mark, the distance of meter rule weight from the pivot can be calculated as follows:
Distance of meter rule weight from the pivot = Total length of meter rule - Distance of 60 cm mark from the pivot
= 100 cm - 60 cm
= 40 cm (converted to meters by dividing by 100)
= 0.40 m
Plugging these values into the equation, we get:
20 N x distance of weight from the pivot = W x distance of meter rule weight from the pivot
20 N x 0.60 m = W x 0.40 m
Now, we can solve for W by rearranging the equation:
W = (20 N x 0.60 m) / 0.40 m
W = 30 N
Therefore, the weight of the meter rule is 30 N.