Question

A bus decreases its speed from 80 kilometre per hour to 60 km per hour find a accerlation of a bus

Answer 1

Correct Question :-

A bus decreases its speed from 80 kilometre per hour to 60 km per hour in 1 hour a accerlation of a bus.

Given:-

• Initial velocity of bus (u) = 80km/h
• Final velocity of bus (v) = 60km/h

• Time taken by bus (t) = 1 hour

To Find:-

• Acceleration of the bus .

Solution:-

Firstly, we convert the given given information into their unit.

Initial velocity = 80km/h = 80 ×5/18 = 400/18m/s

Final velocity = 60km/h = 60×5/18 = 300/18m/s

Time = 1 hour = 1×60×60 = 3600s

Now ,by using first equation of motion

⟹ v = u+at

Put the values which is given above

⟹ 300/18 = 400/18 + a×3600

⟹ 16.66 = 22.22 + a×3600

⟹ 16.66 - 22.22 = a×3600

⟹ -5.56 = a ×3600

⟹ a = -5.56/3600

⟹ a = -0.00154 m/s²

here negative sign show retardation.

∴ The acceleration of bus is 0.00154m/s²

Additional Information !!

✧ The rate of change of velocity at per unit time is called acceleration .

✧ SI unit of acceleration is m/s²

✧ It is vector Quantity ( both magnitude and direction)

Answer 2

✔ Given :-

• Initial Velocity = 80km/h = 400/18 m/s.

• Final Velocity = 60km/h = 300/18 m/s.

• Time = 1 hour = 3600 seconds.

✔ To Find :-

• Acceleration of the bus.

✔ Solution :-

Use First Equation Of Motion.

v = u + at.

Put the values.

➠ 300/18 = 400/18 + 3600a.

➠ 300/18 - 400/18 = 3600a

➠ -100/18 = 3600a.

➠ a = -0.00154 m/s²

Hence, Acceleration = -0.00154 m/s²