Mechanical Engineering - Engineering Mechanics - Discussion

A body will begin to ready just move which angle is called angle of friction.

Can someone please explain pictorially for me angle of friction and angle of inclination thanks.

I did not understood this question.

What is the meaning of angle of friction?

The angle which the resultant (between the normal and external force) makes with the vertical is called the angle of friction.

Just assume that when a body is lies on horizontal plane then it is not move without any external force because there is also a static friction and its value is high on horizontal surface so here the angle of plane surface is zero. But the angle of friction is high. As a plane is going to be achieve an inclination the angle of friction is decreases. And as the angle of friction or simply the friction will decreases the angle of plane is decreases and body will automatically moves downward. So here the angle of plane is higher than the angle of friction.

I think it should begin to move when the angle of inclination is equal to the angle of friction.

As the Angle of Repose is the angle of inclination in which the body begins to move itself.

And the angle of Repose is equal to the angle of Friction. Therefore it should equal to angle of friction.

Does anyone know why its "greater"?

When angle of inclination is equal to the angle of friction, the body just about to move. But don't move. If angle of inclination slightly increases then the body starts to move. So option C is correct.

C is the right answer.

Normally, the vertical force is coefficient of friction so greater than inclined angle near the answer.

Answer A is right because the angle of inclination is equal to the angle of repose.

α= fi.