Question

When a car screeches to a sudden stop to avoid hitting a dog, it slows down from 9.00 m/s to 0.00 m/s in 1.50 s. Find the average acceleration of the car.

Answer 1

The formula for acceleration is

`a=(\Delta v)/(t)`
where
`a=` acceleration,
`\Delta v=` change in velocity, and
`t=` time

So we get

`a=(-9.00\ m/s)/(1.50\ s)`

`\rightarrow a=-6.00\ m/s^(2)`

Answer 2

a = - 6 m/s/s

here negative sign shows that velocity is decreasing with time

Step-by-step explanation:

As we know that average acceleration is given by

`a_(avg) = (v_f - v_i)/(\Delta t)`

here we will have

`v_f` = final speed = 0 m/s

`v_i` = initial speed = 9 m/s

`\Delta t` = time interval = 1.50 s

now from above equation we will have

`a = (0 - 9)/(1.5)`

`a = - 6 m/s^2`

so average acceleration will be -6 m/s/s