Um caminhão viaja pela estrada com velocidade de 70km/h. diante de um obstáculo ele é freado e para cerca de 360 segundos depois. qual foi a aceleração media?

Explanation:

The question in english is written below:

A truck travels along the road at a speed of 70 km/h. It encounters an obstacle and brakes for about 360 seconds until it stops. What is the average acceleration of the truck?

Average acceleration is the variation of velocity over a specified period of time :

Where:

is the initial velocity

the final velocity

Then:

Finally:

Note the negative sign in the acceleration indicates the truck was decreasing its velocity until it stopped.

think about the oscillation of the toy shown in the video. when the toy is at the highest point of its motion, its velocity is zero and its acceleration is negative.

their crystal patterns have been disrupted by stress