Question

Akash slows down from 72 km per hour to 36 kilometre per hour after covering a distance of 25 find total time taken?? please help me
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Answer 1

Refer to the attachment.

Hope this helps you ☺️

Answer 2

Given :-

Initial velocity(u) = 72 km/h = 20 m/s

Final velocity(v) = 36 km/h = 10 m/s

Distance covered(s) = 25 km = 25000 m

To find :-

The total time(t) taken.

Solution :-

We know,

v² - u² = 2as

Now, putting the values :

(10)² - (20)² = 2*a*25000

⇒100 - 400 = 50000a

⇒ -300 = 50000a

⇒a = -0.006 m/s²

We also know,

v = u + at

⇒10 = 20 + (-0.006)*t

⇒ -10 = -0.006t

⇒t = -10/-0.006 = 10/0.006

⇒t = 1666.66 s = 0.462 hrs