The given relation F = mv2, where F is the force, m is the mass and v is the speed of the particle.
The dimension of force F = [MLT-2]
The dimension of velocity, v = [LT-1]
The dimension of mass m = [M]
The dimension of left hand side, F = [MLT-2]
Dimension of the right hand side mv2 = [M][LT-1]2 = [ML2T-2]
Since the dimensions on the left-hand side are not equal to the dimension on the right-hand side of the equation. So, the formula is dimensionally wrong.