Advertisements
Advertisements
प्रश्न
A uniform metre rule rests horizontally on a knife-edge at the 60 cm mark when a mass of 10 gram is suspended from one end. At which end must this mass be suspended? What is the mass of the rule?
Advertisements
उत्तर
Let M gram be the mass of the rule. Since the density of the rule is uniform, its weight Mg will act at its middle point i.e., at the 50 cm mark (Fig.).
The weight of the rule produces an anti-clockwise moment about the knife-edge O. In order to balance it, 10-gram mass is to be suspended at the end B, to produce a clockwise moment.
From the principle of moments,
Anti-clockwise moment = Clockwise moment
Mg × (60 – 50) = 10 g × (100-60)
or Mg × 10 = 10 g × 40
∴ M = 40 gram
संबंधित प्रश्न
The S.I. unit of force is kgf. (kilogram-force)
State the effect of force F in of the following diagram.
Sleepers are used below the rails.
What are non-contact forces? Give two example
A rocket is moving at a constant speed in space by burning its fuel and ejecting out the burnt gases through a nozzle. Answer the following
1) Is there any change in the momentum of the rocket? if yes, what causes the change in momentum?
2) Is there any force acting on the rocket? if yes, how much?
The diagram in the figure shows a uniform metre rule weighing 100 gf, pivoted as its centre O. two weight 150 gf and 250 gf hang from the point A and B respectively of the metre rule such that OA = 40 cm and OB = 20 cm . Calculate
the total anticlockwise moment about o.
Classify the following amongst contact and non-contact forces.
electrostatic force
A jack screw is provided with a long arm. Explain why?
State when the moment of force is positive and when it is negative.
Two unlike forces (parallel) of 10 N and 25 N act at a distance of 12 cm. from each other. Find the point about which the body balance.
