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Interpret velocity-time graph for constant direction and understand significance of area under velocity-time graph.

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VELOCITY-TIME GRAPH FOR CONSTANT DIRECTION: When an object is moving with a constant velocity, the line on the graph is horizontal. When an object is moving with a steadily increasing velocity, or a steadily decreasing velocity, the line on the graph is straight, but sloped. The diagram shows some typical lines on a velocity-time graph.
The steeper the line, the more rapidly the velocity of the object is changing. The blue line is steeper than the red line because it represents an object that is increasing in velocity much more quickly than the one represented by the red line. Notice that the part of the red line between 7 and 10 seconds is a line sloping downwards (with a negative gradient). This represents an object that is steadily slowing down. AREA UNDER VELOCITY-TIME GRAPH:             Study this velocity-time graph. The area under the line in a velocity-time graph represents the distance travelled. To find the distance travelled in the graph above, we need to find the area of the lig…

Derivation of Gravitational Potential Energy (without using Calculus)

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The potential energy of a body at height “h” from centre of earth w.r.t. a point at which the gravitational field is zero i.e. a point which has no potential is called absolute gravitational potential energy.



Where RE is the radius of earth.The minus sign indicates that the potential energy is “negative” at any finite distance that is the potential energy is zero at infinity and decreases as the separation distance decreases. This is due to the fact that the gravitational force acting on the particle by earth is attractive. As the particle moves in from infinity the Work is positive which means U is negative.

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