Question

a car travelling at a speed of 20 metre per second applies brakes in stop it in 10 second what is acceleration of car​

Answer 1

Question:

A car travelling at a speed of 20 metre per second applies brakes in stop it in 10 second.

What is the acceleration of car?

Answer:

Using the properties of motion:

Here, as car comes to rest,

final velocity or v is 0.

Initial velocity or u is 20 m / s

Time taken or t = 10

We know that acceleration is the rate of change of velocity.

So,

Acceleration = ( v - u ) / t

Acceleration = ( 20 - o ) / 10 m/s²

Acceleration = 20/10 m/s²

Acceleration = 2 m/s²

Here , speed / velocity is decreasing with respect to time which is called as retardation .

So here retardation is 2 m / s²

And acceleration is - 2 m / s ²

Negative sign refers decrease in velocity.

Answer 2

✰ Question✰

___________________

▪ A car travelling at a speed of 20 metre per second applies brakes in stop it in 10 second what is acceleration of car.

___________________

➧ Given :-

▪ Initial velocity of car (u)=20m/s

▪Final velocity of car (v) = 0m/s

▪Time taken to stop car (t) =10sec

➧To Find :-

▪ Acceleration of car??

✰Solution ✰

➠ By using first equation of motion

$v = u + at \\ \\ 0 = 20 + a \times 10 \\ - 20 = a \times 10 \\ \\ a = \frac{ - 20}{10} \\ \\ a = - 2ms {}^{ - 2}$

Hence the acceleration of car is 2m/s sq.

✰Additional information✰

➠ The rate at which the velocity of an object changes is called acceleration of the object.

➠ SI unit of acceleration is m/s sq.

➠ It is vector quantity.