Answer:
4000pascal
Explanation:preassure = force/area
F = 400N
A = 50cmx 20cm = 1000 cm sq
so we have to convert the area in metre square
so when convert we get the answer 1/10 = 0.1m square
now as per the equation of preassure we have to divide 0.1/400
and then we get the answer 4000pascal.