A car increases its speed from 54 km/h to 90 km/h in 10s. Its acceleration is-

The correct answer is 1 ms-2

CONCEPT:

•  Acceleration
  • ​It is the first derivative of velocity with respect to time and the second derivative of position with respect to time. Because it has both magnitude and direction, acceleration is a vector quantity. 
  • Types of Acceleration
    • ​Uniform and Non-uniform Acceleration: In a circle where speed stays the same, but the direction changes, the body's velocity changes, and the body is said to be moving faster.
    • Average Acceleration: The total change in velocity divided by the total time it took for the change is the definition of the average acceleration over time.

where a is the vector quantity, Δv is the velocity, and Δt is the time.

• To convert speed from km/h to m/s, we multiply it by 5/18.

Calculation:
Given:

Vi = 54 km/h = 54×5/18 = 15m/s

Vf = 90 km/h = 90×5/18 = 25m/s

\(\overrightarrow{a} = {\overrightarrow{Δ v} \over Δ t} = {\overrightarrow{ v_f} -\overrightarrow{ v_i} \over Δ t}\)
\(\overrightarrow{a} = {25 -15 \over 10}= 1~m/s^2\)