A meter rule is balanced horizontally on a knife edge by a mass of 30kg long 20cm from one end . If the position of the knife edge is 18cm from the center of the rule,what is the weight of the rule
To balance the meter rule on the knife edge, the torque on one side of the knife edge must equal the torque on the other side.
The torque about a point is given by the formula:
Torque = Force × Distance
Let's assume the center of the meter rule is the pivot point.
On one side of the knife edge, the torque is due to the weight of the mass:
Torque1 = (30 kg) × (9.8 m/s^2) × (0.20 m)
On the other side of the knife edge, the torque is due to the weight of the meter rule:
Torque2 = Weight of the Rule × (0.18 m)
Since the meter rule is balanced horizontally, Torque1 = Torque2:
(30 kg) × (9.8 m/s^2) × (0.20 m) = Weight of the Rule × (0.18 m)
Now we can solve for the weight of the rule:
Weight of the Rule = (30 kg) × (9.8 m/s^2) × (0.20 m) / (0.18 m)
Weight of the Rule ≈ 33.33 kg
Therefore, the weight of the rule is approximately 33.33 kg.
mass is in kg
weight is in Newtons
You are correct, and I apologize for the confusion.
To find the weight of the rule, we need to multiply the mass of the rule by the acceleration due to gravity (9.8 m/s^2). The weight of an object is given by the formula:
Weight = Mass × Acceleration due to gravity
Weight of the Rule = Mass of the Rule × Acceleration due to gravity
Weight of the Rule = 30 kg × 9.8 m/s^2
Weight of the Rule = 294 N
Therefore, the weight of the rule is 294 Newtons.
I think you did m g before but just expressed the answer in kg. You do not have to multiply by 9.81 twice.
You are correct, I apologize for the error. To find the weight of the rule, we only need to multiply the mass of the rule by the acceleration due to gravity once.
Weight of the Rule = Mass of the Rule × Acceleration due to gravity
Weight of the Rule = 30 kg × 9.8 m/s^2
Weight of the Rule = 294 N
Therefore, the weight of the rule is 294 Newtons.
To find the weight of the rule, we need to understand the concept of torque. Torque is the turning force that causes an object to rotate around an axis. In this case, the rule is balanced horizontally, which means the torques on both sides of the knife edge are equal.
The torque on one side of the knife edge is calculated by multiplying the force applied by the distance from the knife edge. In this case, the force is the weight of the rule and the distance is 20 cm. The torque on the other side of the knife edge is the product of the unknown weight of the rule and the distance from the knife edge, which is 18 cm.
Since the rule is balanced horizontally, the torques on both sides are equal. Therefore, we can set up the equation as follows:
Weight of the rule * 20 cm = 30 kg * 9.8 m/s^2 * 0.18 m
Here, we convert the 30 kg to its SI unit of mass, which is 9.8 m/s^2. We also convert the distance from cm to meters by dividing it by 100.
Now, let's solve the equation to find the weight of the rule:
Weight of the rule = (30 kg * 9.8 m/s^2 * 0.18 m) / 0.20 m
Weight of the rule = 26.1 kg * 9.8 m/s^2
Weight of the rule = 255.78 N
Therefore, the weight of the rule is approximately 255.78 Newtons.