# Question #90693

##### 1 Answer

Recall the Newton' second Law of motion for an object of mass

where

If a force acts through a displacement

Work done

Using (1) we can write (2) as

Recall the kinematic equation

where

Using (4) equation (3) becomes*

Inserting given values

We know that square of a vector is dot product of vector with itself hence, above equation becomes

*recall that equation is