Explanation:
Given parameters:
Initial velocity = 72km/hr
Final velocity = 0km/hr
Time taken = 25s
Unknown:
Acceleration = ?
Solution:
To solve this problem, convert km/hr to m/s;
1000m = 1km
3600s = 1hr
72km/hr;
1km/hr = 0.278m/s
72km/hr = 0.278 x 72 = 20.02m/s
Acceleration is the change in velocity divided by the time taken;
Acceleration = [tex]\frac{final velocity - initial velocity }{time}[/tex]
Acceleration = [tex]\frac{0 - 20.02}{25}[/tex] = -0.8m/s
The car is actually decelerating at a rate of 0.8m/s