What is evaporation,velocity-time graph,wind speed

Velocity – Time Graphs:

The variation in velocity with time for an object moving in a straight line can be represented by a velocity-time graph. In this graph, time is represented along the x-axis and the velocity is represented along the y-axis. If the object moves at uniform velocity, the height of its velocity-time graph will not change with time. It will be a straight line parallel to the x-axis. To determine the distance moved by the car from its velocity-time graph, the area under the velocity-time graph gives the distance (magnitude of displacement) moved by the car in a given interval of time.

For example, if the car would have been moving with uniform velocity, the distance travelled by it would be represented by the area ABCD under the graph. Since the magnitude of the velocity of the car is changing due to acceleration, the distance s travelled by the car will be given by the area ABCDE under the velocity-time graph.

That is,

s =  area ABCDE =  area of the rectangle ABCD + area of the triangle ADE

=  AB × BC + 1/2 (AD × DE)

In the case of non-uniformly accelerated motion, velocity-time graphs can have any shape.

Speed of a body is defined as the distance travelled by the body in unit time.