Concept:
Two physical quantities have the same dimensional formula when they are expressed using the same powers of mass, length and time.
Step 1: Pressure is defined as force per unit area:
\[
P=\frac{F}{A}
\]
Step 2: Dimension of force is:
\[
[F]=MLT^{-2}
\]
Step 3: Dimension of area is:
\[
[A]=L^2
\]
Step 4: Therefore, dimension of pressure is:
\[
[P]=\frac{MLT^{-2}}{L^2}=ML^{-1}T^{-2}
\]
Step 5: Modulus of elasticity is defined as:
\[
\text{Modulus}=\frac{\text{stress}}{\text{strain}}
\]
Step 6: Strain is dimensionless, and stress has the same dimension as pressure.
\[
[\text{Modulus of elasticity}]=ML^{-1}T^{-2}
\]
Step 7: Hence pressure and modulus of elasticity have the same dimensional formula.
\[
\boxed{\text{Pressure and modulus of elasticity}}
\]