Numericals on Moment of Force class 10

In this post, we will solve a few selected Numericals on Moment of Force for class 10. We have another post on Force Numericals for class 10 where you will find more such numericals to solve.

Numericals on Moment of Force for class 10

Numerical Question 1] The figure shows two forces each of magnitude 10N acting at points A and B at a separation of 50 cm, in opposite directions. Calculate the resultant moment of the two forces about points (i) A, (ii) B, and (iii) O, situated exactly in the middle of the two forces.

Solution

Given,
Force at A = 10N
Force at B = 10N
Distance between A and B = 50cm = 0.5m

(i) Resultant moment of two forces at point A is 10×0.5=5Nm clockwise.

Therefore, the resultant moment of two forces at point A is 5 Nm (clockwise)

(ii) Resultant moment of two forces at point B is=10×0.5=5Nm clockwise

Therefore, the resultant moment of two forces at point B is 5 Nm (clockwise)

(iii) Perpendicular distance of point O from either of the forces F = 10N is 0.25 m

Moment of force F at point A about O=10×0.25=2.5Nm clockwise

Moment of force F at point B about O = 10×0.25=2.5Nm clockwise

The resultant moment of two forces about O is=2.5+2.5=5 Nm clockwise

Therefore, the Resultant moment of two forces about O is 5 Nm (clockwise)

Numerical Question 2] The moment of a force of 10N about a fixed point O is 5Nm. Calculate the distance of point O from the line of action of the force.

Answer

As we know, Moment of Force = Force × Perpendicular distance from the point O

Moment of force = F × r

So, putting the values from the question we get
5 =10 r
=>r = 5/10 m = 0.5 m

Numerical Question 3] A nut is opened by a wrench of length 10 cm. If the least force required is 5.0N, find the moment of force needed to turn the nut.

Answer

It is given that,
Required least force = 5N
r = 10cm = 0.1m

We know, Moment of force = F x r

Substituting the values of F and r
Moment of force = Fr =5×0.1=0.5Nm

Therefore, the moment of force = 0.5 Nm

Numerical Question 4] A wheel of diameter 2m is shown in the figure with an axle at O. A force F = 2N is applied at B in the direction shown in the figure.

Calculate the moment of force about
(i) the center O, and
(ii) point A.

Answer

We know from the question,

F = 2 N
Diameter = 2m
So, Radius or OB = 1m

(i) Moment of force about O = F x r = 2×1 Nm = 2 Nm

(ii) Moment of force about A = F x r = 2×2 Nm=4 Nm