00:01
In the first option which is option a, it is given that it is possible to have forces on an object in the absence of motion of the object.
00:12
So here we can say that if a body is at rest, is at rest the two forces that are acting on the body are.
00:25
One is the weight of the body and the second one is the normal force.
00:32
That is acting on the body.
00:35
Normal force.
00:39
So we can consider a body or an object that is resting on a horizontal surface.
00:46
So the object has mass m and it has weight that is acting downwards.
00:55
So weight w equals m, g where m is the mass of the object and g is the acceleration due to gravity.
01:02
Now the weight of the body is due to the gravitational pull on the mass of the body acting perpendicular to the horizontal plane at which the body is resting.
01:13
So we can say that weight of the body is acting downwards.
01:20
Now the normal reactive force exerted on the body by the horizontal plane which is perpendicular, sorry, which is exactly opposite to the direction of the weight of the body.
01:32
So here we have normal force acting upwards.
01:38
So we can thus say that it is possible to have forces on an object in the absence of motion of the object...