# Velocity along a frictionless surface

## Homework Statement

A body moves down along an inclined plane from A(top) to B(bottom), and then moves on the floor in continuation to some point C. (All surfaces are frictionless)

After reaching B, body is having some acceleration. But while moving from B to C,
a) will it keep on accelerating,
b) or, its acceleration will be zero (constant velocity) from B to C.

2. The attempt at a solution
Frictionless surface don't interfere with the motion of the body, so whatever state body is possessing at B (some velocity), this will continue holding, so body will move with zero acceleration from B to C.

Merlin3189
Homework Helper
Gold Member

The question sounded a bit odd, "After reaching B, body is having some acceleration."
I would say, "Up to point B, body is having some acceleration."

The question sounded a bit odd, "After reaching B, body is having some acceleration."
I would say, "Up to point B, body is having some acceleration."

Body is having acceleration at B as it has accelerated from A to B, question is about from B to C.

The speed will remain constant from B to C
Why?
Well
Because B and C are on the same horizontal level
And thus there's no question of vertical motion here (they surely aren't going to break the floor and move
And since the horizontal components of the forces acting on the block (gravity and the normal force) are zero
And since there's no friction
The block will keep moving with a constant velocity from B to C

UchihaClan13

rashida564 and Anjum S Khan
The speed will remain constant from B to C
Why?
Well
Because B and C are on the same horizontal level
And thus there's no question of vertical motion here (they surely aren't going to break the floor and move
And since the horizontal components of the forces acting on the block (gravity and the normal force) are zero
And since there's no friction
The block will keep moving with a constant velocity from B to C

UchihaClan13

I was confused about the acceleration part.

Don't be then :)
The block accelerates from A to B because as there's no friction,the force mgsinθ which acts down the incline,accelerates the block
Over the entire distance the block traverses/moves
Once it reaches B,there is a momentary transition and there's some initial acceleration from B to C
But its momentary and thus it can be neglected!

UchihaClan13

Like others have, the speed of the body from B to C will remain constant since there's no force acting on it due to gravity.