Question

what is the dimensional formula and units of linear momentum

Answer 1

Linear Momentum = Mass x Velocity

Now
Velocity = Displacement/Time
Velocity = L/T
So
Linear Momentum= M x LT^-1

So Dimensional Formula of Linear Momentum=[ M^1, L^1,T^-1] 
SI unit of Linear Momentum is kg ms^-1

Answer 2

MLT^-1 it is the dimension