Question

an object moving with the speed of 40 km/ h it stop after 30 minutes. find the acceleration of object​

Answer 1

Given:-

• Initial velocity ,u = 40km/h
• Final velocity ,v = 0km/h
• Time taken ,t = 30min = 1/2 hour

To Find:-

• Acceleration ,a

Solution:-

According to the Question

As we know that acceleration is defined as the rate of change in velocity .

• a = v-u/t

where,

• v is the final velocity
• a is the acceleration
• u is the initial velocity
• t is the time taken

Substitute the value we get

$:\implies$ a = 0-40/1/2

$:\implies$ a = -40×2/1

$:\implies$ a = -80/1

$:\implies$ a = -80km/h²

Here, negative sign show retardation

• Hence the acceleration of the object is 80km/h²

Answer 2

Given :-

An object moving with the speed of 40 km/h it stop after 30 minutes

To Find :-

Acceleration

Solution :-

We know that

1 km/h = 5/18 m/s

40 km/h = 40 × 5/18 = 11.11 m/s

and

1 min = 60 sec

30 min = 30 × 60 = 1800 sec

Now

a = v - u/t

a = 0 - 11.11/1800

a = -11.11/1800

a = -0.006 m/s²