Question

When the shuttle bus comes to a sudden stop

to avoid hitting a dog, it decelerates uniformly
at 3.8 m/s2 as it slows from 9.8 m/s to 0 m/s.
Find the time interval of acceleration for
the bus.
Answer in units of s

Answer 1

The question is asking to calculate the time interval of acceleration for the bus and base on my own calculation, I would say that the answer would be 2.58 seconds. I hope you are satisfied with my answer and feel free to ask for more. I hope you are satisfied with my answer and feel free to ask for more 

Answer 2

2.58 seconds

Explanation:

Given: the shuttle bus comes to a sudden stop to avoid hitting a dog, it decelerates uniformly at
`3.8`
`\text{m}/\text{s}^2` as it slows from
`9.8`
`\text{m}/\text{s}` to
`0`
`\text{m}/\text{s}`.

To Find: the time interval of acceleration for the bus.

Solution:

Initial speed of shuttle bus
`\text{u}=9.8`
`\text{m}/\text{s}`

Final speed of shuttle bus
`\text{v}=0`
`\text{m}/\text{s}`

acceleration
`=3.8`
`\text{m}/\text{s}^2`

using first equation of motion

`\text{v}=\text{u}+\text{a}\text{t}`

as speed decreases acceleration will be negative

`\text{v}=\text{u}-\text{a}\text{t}`

putting value in equation

`0=9.8-3.8\text{t}`

`3.8\text{t}=9.8`

`\text{t}=(9.8)/(3.8)`

`\text{t}=2.58`
`\text{seconds}`

It takes
`2.58\text{s}` to decelerate to
`0`
`\text{m}/\text{s}`