Recall the formula for momentum.

Momentum ($p$) is the product of mass ($m$) and velocity ($v$).

$$p = mv$$

The dimension of mass is $[M]$.
The dimension of velocity is $[L][T]^{-1}$ (length per unit time).

$$[p] = [M] \times [L][T]^{-1}$$

The dimension of momentum is $\boxed{\text{[M][L][T]}^{-1}}$.

Pressure ($P$) is force ($F$) per unit area ($A$).

$$P = \frac{F}{A}$$

The dimension of force is $[M][L][T]^{-2}$ (from $F=ma$, where $a$ is acceleration $[L][T]^{-2}$).
The dimension of area is $[L]^2$.

$$[P] = \frac{[M][L][T]^{-2}}{[L]^2} = [M][L]^{1-2}[T]^{-2}$$

The dimension of pressure is $\boxed{\text{[M][L]}^{-1}\text{[T]}^{-2}}$.

Surface tension ($\gamma$) is force ($F$) per unit length ($L$).

$$\gamma = \frac{F}{L}$$

The dimension of force is $[M][L][T]^{-2}$.
The dimension of length is $[L]$.

$$[\gamma] = \frac{[M][L][T]^{-2}}{[L]} = [M][L]^{1-1}[T]^{-2}$$

The dimension of surface tension is $\boxed{\text{[M][T]}^{-2}}$.

Power ($P$) is work done ($W$) per unit time ($t$).

$$P = \frac{W}{t}$$

Work is force times distance ($W = F \cdot d$).
The dimension of force is $[M][L][T]^{-2}$.
The dimension of distance is $[L]$.
So, the dimension of work is $[W] = [M][L][T]^{-2} \times [L] = [M][L]^2[T]^{-2}$.
The dimension of time is $[T]$.

$$[P] = \frac{[M][L]^2[T]^{-2}}{[T]} = [M][L]^2[T]^{-2-1}$$

The dimension of power is $\boxed{\text{[M][L]}^2\text{[T]}^{-3}}$.