Which one among the following statements is correct ?

The correct statement is that Pascal (Pa) and N/m² represent the same unit of pressure. Pressure is defined as force per unit area, and its SI unit is the newton per square metre (N/m²), which is officially named the pascal [3]. Statement 1 is incorrect because pressure is a scalar quantity; while the force acting on a surface has direction, pressure at a point in a fluid acts equally in all directions [4]. Statement 2 is incorrect because hydrostatic pressure increases with depth due to the weight of the fluid column above, calculated as P = ρgh [5]. Statement 3 is incorrect because, according to Newton's third law, action and reaction forces always act on two different objects, not the same one. Therefore, only the unit equivalence in statement 4 is scientifically accurate.

Sources

1. [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 6: Pressure, Winds, Storms, and Cyclones > Snapshots > p. 94
2. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 6: Pressure, Winds, Storms, and Cyclones > 6.1 Pressure > p. 82
3. [3] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 6: Pressure, Winds, Storms, and Cyclones > A step further > p. 87
4. [4] https://en.wikipedia.org/wiki/Pressure
5. [5] https://www.grc.nasa.gov/www/k-12/WindTunnel/Activities/fluid_pressure.html