GK
PHYSICS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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sand is soft and concreter is hard
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the sand is grainy but concrete is smooth
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the friction between sand and feet is less than that between concrete and feet
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the friction between sand and feet is more than that between concrete and feet
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Detailed explanation-1: -Since the particles of sand are small granules, when we move our feet through then, the granules also move, thus providing a very weak resistive force against our feet. Since the friction is less, it is difficult to walk on sand. This makes it harder for us to walk on sand as compared to a road or footpath.
Detailed explanation-2: -In fact, moving on sand uses up 1.6x more energy than on a hard surface. Reason being, the mechanical work getting your body to move in the forgiving ground, and the inefficiency of the work done by tendons and muscles due to the sand’s unpredictable surface. In other words, running 20 minutes through pliable dry sand.
Detailed explanation-3: -Thus because of this there’s very little friction between the bottoms of your shoes and the ice and the person will slip because of this. Hence, it is difficult to walk on the ice than on the road because Ice has a lesser friction than the road.
Detailed explanation-4: -ice is soft and spongy where as concrete is hard. the friction between the ice and the feet is less than that between the concrete and feet.
Detailed explanation-5: -Since on ice there is no frictional force, the foot slips when he tries to exert force on ice to make himself move forward.