How do we calculate value of frictional force given the mass and constant velocity?

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1 Answer
Mar 6, 2018

A. #600N#

B. #2400N#

Explanation:

Well,when the elephant is applying some amount of force in pulling the car,but still it is moving with constant velocity,that means the system is in equilibrium.What is meant by this sentence is that,there must be some opposing force of same magnitude as the applied force by the elephant,which is resulting in this equilibrium.

So,frictional force acting = force applied by the elephant in pulling it with constant velocity=#600 N#

Now,supposing that maximum value of frictional force acting is #600N#,we can say that if the elephant now exerts a force of #F#,then acceleration of the system will be #1.5 ms^-2# due to the net force #(F-600)N# acting forwards.

So,we can write,

Acceleration=#a=1.5=(F-600)/m=(F-600)/1200#

Or,#F=600+1200×1.5=2400N#