Question

mark the direction of frictional force, and mention the kind of frictional force that comes into play, in each

Answer 1

Friction came into play when it irregularities have been present in the surface of two objects.

It the direction is in opposite to the motion, the body aligned to the center and hence frictional force is always directed in the opposite direction.

Therefore, lesser force is required to overcome interlocking.

Answer 2

ᶠʳⁱᶜᵗⁱᵒⁿ ᶜᵃᵐᵉ ⁱⁿᵗᵒ ᵖˡᵃʸ ʷʰᵉⁿ ⁱᵗ ⁱʳʳᵉᵍᵘˡᵃʳⁱᵗⁱᵉˢ ʰᵃᵛᵉ ᵇᵉᵉⁿ ᵖʳᵉˢᵉⁿᵗ ⁱⁿ ᵗʰᵉ ˢᵘʳᶠᵃᶜᵉ ᵒᶠ ᵗʷᵒ ᵒᵇʲᵉᶜᵗˢ. 

ⁱᵗ ᵗʰᵉ ᵈⁱʳᵉᶜᵗⁱᵒⁿ ⁱˢ ⁱⁿ ᵒᵖᵖᵒˢⁱᵗᵉ ᵗᵒ ᵗʰᵉ ᵐᵒᵗⁱᵒⁿ, ᵗʰᵉ ᵇᵒᵈʸ ᵃˡⁱᵍⁿᵉᵈ ᵗᵒ ᵗʰᵉ ᶜᵉⁿᵗᵉʳ ᵃⁿᵈ ʰᵉⁿᶜᵉ ᶠʳⁱᶜᵗⁱᵒⁿᵃˡ ᶠᵒʳᶜᵉ ⁱˢ ᵃˡʷᵃʸˢ ᵈⁱʳᵉᶜᵗᵉᵈ ⁱⁿ ᵗʰᵉ ᵒᵖᵖᵒˢⁱᵗᵉ ᵈⁱʳᵉᶜᵗⁱᵒⁿ. 

ᵗʰᵉʳᵉᶠᵒʳᵉ, ˡᵉˢˢᵉʳ ᶠᵒʳᶜᵉ ⁱˢ ʳᵉզᵘⁱʳᵉᵈ ᵗᵒ ᵒᵛᵉʳᶜᵒᵐᵉ ⁱⁿᵗᵉʳˡᵒᶜᵏⁱⁿᵍ.