NEET Physics Mathematical Tools Questions Solved

Initial kinetic energy of the body $=\frac{1}{2}m{u}^2 =\frac{1}{2}\times 25\times {\left(2\right)}^2=50 J$

Final kinetic energy= Initial energy - work done against resistive force (Area between graph and displacement axis)
$= 50-\frac{1}{2}\times 4\times 20 =50-40 =10 J$

If kinetic energy of the body increases, work is positive i.e. body moves in the direction of the force (or field) and if kinetic energy decreases work will negative and object will move opposite to the force (or field).