Atividade 1 - Um caminhão de 20 m de comprimento desenvolve uma velocidade constante numa estrada retilínea e plana. Ele demora 10 s para atravessar uma ponte de 180 m de extensão. Calcule a velocidade do caminhão, em km/h.

   v = 64.8 km / h

Explanation:

This is a uniform rectilinear motion exercise, the speed is

        v = d / t

where d is the distance traveled and t the time to travel the distance

the bridge has d = 180 m and runs it at t = 10 s, we use a reference point on the truck for measurement

    V = 180/10 .v = 18 m / s

we reduce to km / h

    v = 18 m / s (1 km / 1000m) (3600 s / 1 h)

     v = 64.8 km / h

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.

multiple