Question

A girl weighing 50 kg is standing on a pencil heel

each having an area of cross section 1 cm ²
An elephant weighing 200kg on a foot of a cross section
of 250cm² standing on a floor

Answer 1

To compare the pressure exerted by the girl and the elephant, we can calculate the pressure using the formula:

Pressure = Force / Area

For the girl standing on the pencil heel:

Weight of the girl = 50 kg
Area of cross section of the pencil heel = 1 cm²

Since pressure is force per unit area, the force exerted by the girl can be calculated using her weight:

Force = Weight × Acceleration due to gravity
= 50 kg × 9.8 m/s² (approximate value for acceleration due to gravity)

Now we can calculate the pressure exerted by the girl:

Pressure = Force / Area
= (50 kg × 9.8 m/s²) / (1 cm²)
= (50 kg × 9.8 m/s²) / (0.0001 m²) (since 1 cm² = 0.0001 m²)

For the elephant standing on the floor:

Weight of the elephant = 200 kg
Area of cross section of the elephant's foot = 250 cm²

Similarly, we can calculate the pressure exerted by the elephant:

Pressure = (200 kg × 9.8 m/s²) / (250 cm²)
= (200 kg × 9.8 m/s²) / (0.025 m²) (since 250 cm² = 0.025 m²)

By comparing the pressures exerted by the girl and the elephant, we can determine which one exerts a higher pressure.