Answer:
779.87 N/m²
Step-by-step explanation:
Pressure = Force (F) / Area (A)
Recall :
Force = ma ; mass * acceleration due to gravity
a = 9.8 m/s² ; mass = 0.4kg
Force, F = 0.4 * 9.8 = 3.92 N
Area = πr² ; r = Radius = 4cm = 4 / 100 = 0.04 m
Area = π0.04² = 0.0050265 m²
Hence,
Pressure = 3.92 / 0.0050265
Pressure = 779.86670 N/m²
Pressure = 779.87 N/m²