Velocity and Distance Calculation (PDF)

(iii)Inthe third case, the train travels at a speed of 70 km/h tor a time of 0.71hours. Again, Speed So, 70 And, Distance = llrrr. = Di:t1"' 0.7r Distance = 70 x 0.7L = 49.7 km.... (3) Now, from the equations (1), (2) and (3), we get: Total distance travelled = 31.2 + 7.2 + 49.7 = 88.1 km And,...(4)...

(iii)Inthe third case, the train travels at a speed of 70 km/h tor a time of 0.71hours. Again, Speed So, 70 And, Distance = llrrr. = Di:t1"' 0.7r Distance = 70 x 0.7L = 49.7 km.... (3) Now, from the equations (1), (2) and (3), we get: Total distance travelled = 31.2 + 7.2 + 49.7 = 88.1 km And,...(4) Total time taken = 0.52 + 0.24 + 0.71 = We know that: Average speed = 1.47 h.... (s) Total distance travelled m 88.1 t.47 = ffi 59.9 km/h The speed of a car (or any other body) gives us an idea of how fast the car is moving but it does not tell us the direction in which the car is moving. Thus, to know the exact position of a moving car we should also know the direction in which the car is moving. In other words, we should know the speed of the car as well as the direction of speed. This gives us another term known as velocity which can be defined as follows: Velocity of a body is the distance travelled by it per unit time in a given direction. That is: - Velocity Distance travelled in a given direction = If a body travels a distance i'in time 'f in a given direction, then its velocity 'v'is given by s V= t where, and body y = velocity of the s = distance travelled (in the given direction) (to travel that distance) f = time taken We know that the 'Distance travelled in a given direction' is known as 'Displacement'. So, we can also write the definition of velocity in terms of 'Displacement'. We can now say that: Velocity of a body is the displacement produced per unit time. We can obtain the velocity of a body by dividing the'Displacement'by'Time taken for the displacement. Thus, we can write another formula for velocity as follows: Distance ,: t Time taken t s = displacement of the body v = veiocity of the body and f = time taken (for displacement) '- velocitv where, 22 Motion