Calculating Acceleration of a Car:
Acceleration is the rate at which an object's velocity changes over time. In this case, we are given the initial speed of the car as 40 km/hr, the final speed as 60 km/hr, and the time taken for this change as 5 seconds. We can use these values to calculate the acceleration of the car.
- Initial Speed (u): 40 km/hr
- Final Speed (v): 60 km/hr
- Time taken (t): 5 seconds

Calculating Acceleration:
Acceleration (a) can be calculated using the formula:
a = (v - u) / t
Substitute the given values into the formula:
a = (60 - 40) / 5
a = 20 / 5
a = 4 km/hr²
Therefore, the acceleration of the car is 4 km/hr². This means that the car's speed is increasing by 4 km/hr every second.

Explanation:
When the car's speed changes from 40 km/hr to 60 km/hr in 5 seconds, it means that the car's velocity is increasing. The acceleration of 4 km/hr² indicates how quickly this change in velocity is occurring. The positive value of acceleration shows that the car is speeding up.
Acceleration is an important concept in physics and is used to describe the rate at which an object's velocity changes. In this case, the acceleration of the car helps us understand how quickly its speed is increasing over time.