Question

Q1.4. A bus decreases its speed from 80 km/hg to 60 km/h
in 5 sec. Find the acceleration of the bus.​

Answer 1

Explanation:

✬ Acceleration = – 1.11 m/s² ✬

Explanation:

Given:

Initial velocity of bus is 80 km/h.

Final velocity of bus is 60 km/h.

Time is 5 seconds.

To Find:

What is the acceleration of the bus ?

Formula to be used:

v = u + at

Solution: Let the acceleration of bus be a m/s. First of all let's change the km/h into m/s. For this we need to multiply by 5/18.

➨ Initial velocity (u) = 80 × 5/18

• u = 400/18 = 22.22 m/s

➨ Finial velocity (v) = 60 × 5/18

• v = 300/18 = 16.67 m/s

Now put all the values on above formula

⟹ v = u + at

⟹ 16.67 = 22.22 + a × 5

⟹ 16.67 – 22.22 = a × 5

⟹ – 5.55/5 = a

⟹ – 1.11 m/s² = a

Hence, acceleration of bus is –1.11 m/s².