Final answer:
The girl exerts a larger force on the ground, about 10 times greater than the force exerted by the elephant.
Step-by-step explanation:
Physics: Pressure and Force
To determine which exerts a larger force on the ground, we need to compare the pressures exerted by the elephant and the girl. Pressure is defined as force divided by area, so we can use the formula:
Pressure = Force / Area
The force exerted by the elephant is 40,000 N and the area of its foot is 1000 cm². Therefore, the pressure is:
Pressure by elephant = 40,000 N / 1000 cm² = 40 N/cm²
The force exerted by the girl is 400 N and the area of her stiletto heel is 1 cm². Therefore, the pressure is:
Pressure by girl = 400 N / 1 cm² = 400 N/cm²
Comparing the two pressures, we can see that the girl exerts a larger force on the ground. The girl exerts a force about 10 times greater than the force exerted by the elephant.