Question

A dog is running 5 m/s west and sees a cat

directly ahead and speeds up to 7 m/s in
the same direction in 2.45 s. What is the
acceleration of the dog during this time?
A 1.81 m/s? W B 2.81 m/sW
C 0.81 m/s?w D 3.81 m/s?w

Answer 1

C 0.81 m/s (I think, I got around 0.8163, so C seems to be the correct answer)

Step-by-step explanation:

First, we need the acceleration formula:

a =
`(delta v)/(delta t) = (v_(f) - v_(i) )/(t)`

where:

-
`v_(f)` is the final velocity (speed with direction, which we have, it's west)

-
`v_(i)` is the starting velocity

- t is total time

Then we plug in what we know and solve:

a =
`(7 - 5)/(2.45)`

a =
`(2)/(2.45)`

a = 0.81632 etc

So our answer becomes 0.82 (they did not round and just cut it off, so we get) C 0.81 m/s as our answer!

Hope this helps :))