Find the average acceleration of a northbound subway train that slows from 12 m/s to 9.6 m/s in 0.9 s

question options:

-2.7 m/s2

2.7 m/s2

2.7 m/s

-2.7 m/s

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

it breaks and dirupture other materials and other sencews from the bottom