Question

A bus accelerates uniformly form 54km/hr to 72km/hr in 10sec. calculate acceleration in km/hr and m/s ?​

Answer 1

Answer:

Acceleration = Change in velocity / Time

                    = v - u / t

72km/h = 72 × 5 / 18 m/s = 20m/s

54km/h = 54 × 5 / 18m/s  = 15m/s

    Acceleration = 20-15 / 10 

                          = 5 /10 

                          = 0.5 m/s²

To find distance we use the formula 

             v² = u² + 2aS   here v is the final velocitiy (72km/h)

                                             u is the initial velocity(54km/h)

                                              a is the acceleration

                                             S is the distance

            20² = 15² + 2 × 0.5 × S 

            400 = 225 + 1×S

            400 - 225 = S

          S = 175 m

Therefore distance = 175m

Answer 2

Acceleration = Change in velocity / Time

= v - u / t

72km/h = 72 × 5 / 18 m/s = 20m/s

54km/h = 54 × 5 / 18m/s = 15m/s

Acceleration = 20-15 / 10

= 5 /10

= 0.5 m/s²

To find distance we use the formula

v² = u² + 2aS here v is the final velocitiy (72km/h)

u is the initial velocity(54km/h)

a is the acceleration

S is the distance

20² = 15² + 2 × 0.5 × S

400 = 225 + 1×S

400 - 225 = S

S = 175 m

Therefore distance = 175m