Let's find the dimensional formulae of the given physical quantities:
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Pressure: Pressure is defined as force per unit area.
Dimensions of Force = [MLT−2]
Dimensions of Area = [L2]
Therefore, Dimensional formula of Pressure = [L2][MLT−2]=[ML−1T−2]
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Force: Its dimensional formula is [MLT−2].
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Momentum: It is the product of mass and velocity.
Dimensional formula of Momentum = [M][LT−1]=[MLT−1].
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Young's modulus of elasticity: It is defined as the ratio of tensile (or compressive) stress to the longitudinal strain.
Stress = Force / Area, so its dimensions are same as pressure, i.e., [ML−1T−2].
Strain = Change in length / Original length, which is dimensionless [M0L0T0].
Therefore, Dimensional formula of Young's modulus = [M0L0T0][ML−1T−2]=[ML−1T−2].
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Coefficient of viscosity: Its dimensional formula is [ML−1T−1].
From the above, we can see that the dimensional formula of Young's modulus of elasticity is the same as that of pressure.