Advertisements
Advertisements
प्रश्न
Fig. shows a uniform meter scale weighing 100 N pivoted at its centre. Two weights of 500 N and 300 N are hung from the ruler as shown in fig.
(i) Calculate total clockwise and anticlockwise moments.
(ii) Calculate difference in clockwise moment and anticlockwise moment.
(iii) Calculate the distance from O where a 100 N weight should be suspended to balance the meter scale.
Advertisements
उत्तर
Let the weight 500 N be hung from the 40cm mark and the weight 300N be hung from the 80 cm mark
(i) Then, total clockwise moment = 500 x (50 - 40) = 500 x 10 = 5000 Nm
Total anticlockwise moment = 300 x (80 - 50) = 300 x 30 = 9000 Nm
(ii) Difference in clockwise and anticlockwise moment = 9000 - 5000 = 4000Nm
(iii) Let the 100 N weight be hung at a distance 'd' from the point 'o' to its left
Then,total clockwise moment = 5000 + 100 d
In balanced condition, sum of clockwise moments = sum of anticlockwise moments
5000 + 100 d = 9000
or 100 d = 4000
or d = 40cm
the weight 100 N should be a hung from the 40cm mark so as to balance the scale.
APPEARS IN
संबंधित प्रश्न
State two effects of a force when applied on a body.
State Newton's third law of motion.
A car of mass 600 kg is moving with a speed of 10 m-1 while a scooter of mass 80 kg is moving with speed of 50 m s-1. which vehicle will require more force to stop it in the (1) same interval of time (2) same distance
Give an example of the following uses of a machine:
to change the direction of force
Fig. 5 shows a uniform meter scale weighing 200 gf. Provided at its centre. Two weights 300 gf and 500 gf are suspended from the ruler as shown in the diagram. Calculate the resultant torque of the ruler and hence calculate the distance from mid-point where a 100 gf should be suspended to balance the meter scale.
Three forces A, B and C are acting on a rigid body which can turn about O in fig.9. If all the three forces are applied simultaneously, in which direction will the body move? Explain.
The diagram shows a uniform metre rule weighing 100gf, pivoted at its centre O. Two weights 150gf and 250gf hang from the point A and B respectively of the metre rule such that OA = 40 cm and OB = 20 cm. Calculate :
the difference of anticlockwise and clockwise moment
Give any two effects of a force on a non-rigid body.
A uniform metre scale is balanced at a 40 cm mark when weights of 20 gf and 5 gf are suspended at 5 cm mark and 75 cm mark respectively. Calculate the weight of metre scale.
A person standing in front of a cliff fires a gun and hears its echo after 3 s. If the speed of sound in air is 336 ms−1.
- Calculate the distance of the person from the cliff.
- After moving a certain distance from the cliff, he fires the gun again, and this time the echo is heard 1.5 s later than the first. Calculate the distance that the person moved.
