Question

A force of 150 N is continuously applied to an object with a mass of 11 kg over a distance of 2.5 m.The object slides over a surface with a coefficient of kinetic friction of .3.How fast is the object moving immediately after the force ceases to be applied?

Answer 1

Final velocity will be 7.31 m/sec

Step-by-step explanation:

We have given applied force F = 150 N

Mass of the object m = 11 KG

Distance traveled by the object s = 2.5 m

Coefficient of kinetic friction
`\mu _k=0.3`

Acceleration due to gravity
`g=9.8m/sec^2`

So frictional force applied on the object
`f=-\mu _kmg=-0.3* 11* 9.8=-32.34N`

So net force = 150-32.34 = 117.66 N

As work done us equal to
`W=Fs`

So work done =
`117.66* 2.5=294.15j`

Now according to work energy theorem work done is equal to change in kinetic energy

So
`(1)/(2)mv^2=294.15`

`(1)/(2)* 11* v^2=294.15`

v =7.31 m/sec

So velocity final velocity will be 7.31 m/sec