Using a horizontal force of 200 N, we intend to move a wooden cabinet across a floor at a constant velocity. What is the friction force that will be exerted on the cabinet?

AcademicPhysicsNCERTClass 9

Given:

Using a horizontal force of 200 N, we intend to move a wooden cabinet across a floor at a constant velocity.

To do:

To find the friction force that will be exerted on the cabinet.

Solution:

The cabinet is moving across a floor at a constant velocity. So, there is no change in velocity. If there is no change in velocity, then there is no change in acceleration. Therefore, acceleration is zero. 

If there is no acceleration, it means the net force is also zero.

Calculation of friction offered by the floor

Here, $\boxed{F_{net}=F_{friction}+F_{applied\ force}}$

Here, $F_{net}\rightarrow$ Net force on the cabinet

$F_{friction}\rightarrow$ Friction exerted on the cabinet

$F_{applied\ applied}\rightarrow$ Applied force

Here, the net force is zero.

So, $0=F_{friction}+F_{applied\ force}$

Or, $0=F_{friction}+200\ N$

Or, $F_{friction}=-200\ N$

Conclusion:

Therefore, friction exerted on the cabinet is $-200\ N$. Here negative sign implies that the friction is acting in opposite direction.

raja
Updated on 10-Oct-2022 13:22:32

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