Give reasons why :
(a) An object thrown upwards reaches a certain height and falls down.
(b) We sprinkle talcum powder on a carrom board.
(c) The ramp on a railway station has a rough surface.
(d) We oil our bicycles regularly.
Give reasons why :
(a) An object thrown upwards reaches a certain height and falls down.
(b) We sprinkle talcum powder on a carrom board.
(c) The ramp on a railway station has a rough surface.
(d) We oil our bicycles regularly.
(a) As we know, the Earth pulls everything towards itself. When an object has been thrown with a particular speed, its motion is affected by gravity. So, the motion of the object in an upward direction decreases gradually and becomes zero at a particular height. After this it falls under the influence of gravity and its motion increases continuously.
(b) We sprinkle talcum powder on the board to reduce the friction between the striker and the carrom board. This helps the striker to move smoothly on the board.
(c) We know that the roughness of the surface increases the friction and this allows us to walk on it. It is very difficult to walk on a smooth surface. Due to this reason, the ramp on a railway station has a rough surface.
(d) We oil our bicycles regularly to avoid it from wearing out by reducing the friction it produces.
(a) As we know, the Earth pulls everything towards itself. When an object has been thrown with a particular speed, its motion is affected by gravity. So, the motion of the object in an upward direction decreases gradually and becomes zero at a particular height. After this it falls under the influence of gravity and its motion increases continuously.
(b) We sprinkle talcum powder on the board to reduce the friction between the striker and the carrom board. This helps the striker to move smoothly on the board.
(c) We know that the roughness of the surface increases the friction and this allows us to walk on it. It is very difficult to walk on a smooth surface. Due to this reason, the ramp on a railway station has a rough surface.
(d) We oil our bicycles regularly to avoid it from wearing out by reducing the friction it produces.
