Question

a girl of mass 40kg stand on her feet of surface area 80cm (g=10m/s) the pressure exerted by her feet is

Answer 1

Required Answer:

Given:

• Mass of the girl (m) = 40kg
• Area (A) = 80cm² = 0.008m²
• Acceleration (a) = 10m/s²

To calculate:

• Pressure exerted by her (P)

Calculation:

We know that,

• ${\underline {\boxed {\Large {\bf \gray { P = \dfrac{F}{A}} }}}}$

Where,

• P = pressure
• F = force
• A = area

Let's calculate the force first:

$\sf { \longmapsto F = ma }$

$\sf { \longmapsto F = 40 \times 10 }$

$\sf { \longmapsto F = 400N }$

Therefore, force is 400N.

Now, substituting values in the formula of force:

$\sf { \longmapsto P =\dfrac{F}{A} }$

$\sf { \longmapsto P =\dfrac{400}{0.008} }$

$\sf { \longmapsto P =\dfrac{400 \times 1000}{8} }$

$\sf { \longmapsto P =\dfrac{400000}{8} }$

$\boxed{\sf { \longmapsto P = 50,000 \: Pa} }$

Therefore, pressure exerted by the girl is 50,000 Pa.

▬▬▬▬▬▬▬▬▬▬▬

Extra!

Pressure

• Pressure is defined as force per unit area.

• SI unit of pressure is N/m².

• N/m² is also called 'Pascal'.

• When the area is large, pressure is less.

• When the area is small, pressure is more.
• Formula : P = F/A

• Dimensional formula of pressure = $\sf { {M}^{1} {L}^{-1} {T}^{-2} }$

▬▬▬▬▬▬▬▬▬▬▬