Understanding Speed
• We see the moving vehicles <br />• Walking people <br />• Running trains <br />• If I ask you how fast or slow these objects are moving, can you tell me? <br />• Cars are fast (CU kids telling) <br />• Walking is slow (CU kids telling) <br />• Train is very fast (CU kids telling) <br />• But if we want to measure accurately how fast and slow these machines are we’ve to know their speed. <br />• Speed is “the distance traveled in unit time” <br />• Its symbol is v <br />• Formula of speed is measured by dividing total distance covered in unit time. <br />• Mathematically its is represented as v is equal to d over t <br />• Here v is representing speed, d is used for distance and t is used for time. <br />• Unit of speed is meter per second. <br />• Speed is a scalar quantity. <br />• Let’s take an example <br />• Suppose here’s a stop-watch and here’s a bi-cycle on clean road. <br />• It moves from this tree to that house. <br />• Look it covered 200 meters in 5 sec. <br />• So its speed is 40m/sec.