Is the pressure exerted on ground more when a person is walking than when he is standing? Why?
The motion of walking is such that at a given point of time, only one of his feet is on the grond.
Since,
Pressure = Force/ Unit Area,
the weight of the person falls on a smaller area of the ground when he's walking than when he's standing on his two feet.
Hence, when the person walks, he exerts more pressure on the ground than when he's standing on his two feet.
Air is thrown on a sail attached to a boat from an electric fan placed on the boat. Will the boat start moving?
Why is the tip of a sewing needle made sharp?
Give two examples to show that air exerts pressure.
What is pressure? What is the relation of pressure with area on which it is applied?
