What is the deceleration of a truck that takes 8.5 seconds to decrease its velocity from 35 m/s to 5 m/s?

It will decelerate at the rate of .

Explanation:

Initial speed of the truck, u = 35 m/s

Final speed, v = 5 m/s

Time, t = 8.5 s

We need to find the deceleration of the truck. As the speed is becoming less, it means it will decelerate. It can be calculated as follows :

So, it will decelerate at the rate of .

it is a negative acceleration

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me