In a situation the contact force by a rough horizontal surface on a body placed on it has constant magnitude. If the angle between this force and the vertical is decreased, the frictional force between the surface and the body will
(i) increase.
(ii) decrease.
(iii) remain the same.
(iv) may increase or decrease.
Answers
Answer ⇒ Option (b).
Explanation ⇒ Let the magnitude of the Fore be F.
Now, If it is making an angle α with the vertical and this angle is continuously decreasing and becomes θ, then the vertical component will be FCosθ and Horizontal Component will be FSinθ.
Since, F Sinθ will be balanced by the Frictional Force.
Mathematically, Frictional Farce = F Sinθ
Now, this may be possible that the angle will continuously to decrease. Now, If the angle of sine is decreasing then the value will also decrease.
∴ Frictional force will decrease.
Hence, Option (b). is correct.
Hope it helps.
Answer:
Explanation:In the situation when the angle between the contact force and vertical decreases, friction force also decreases. Let the contact force has the magnitude F and it makes an angle θ with the vertical then Fcosθ will be the normal force on the body and Fsinθ will be the friction force. As F is constant , decrease in θ decreases Fsinθ and so friction.