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Newton’s Laws of Motion — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysicsNewton’s Laws of Motion2 Marks
Question
If you jump barefooted on a hard surface, your legs get injured. But they are not injured if you jump on a soft surface like sand or pillow. Explain.
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Answer

In both the cases, change in momentum is same but the time interval during which momentum changes to zero is less in the first case. So, by $\text{F}=\frac{\text{dP}}{\text{dt}},$ force in the first case will be more. That’s why we are injured when we jump barefoot on a hard surface.

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