Question

from a rest state, a car starts to accelerate uniformly. This movement lasts for 5 seconds. The speed increases to 25m / s. then the car runs unilaterally straight for 20 seconds


calculate
a. the acceleration in the first 5 seconds
b. the distance traveled during the uniform rectilinear movement.
c. the distance traveled by the entire movement
d. the average speed of the entire movement

Answer 1

a.  acceleration = increase in speed/time = 25/5 = 5m/s²

b. distance travelled during uniform rectilinear movement =  25 x 20 = 500m

c. distance traveled by entire movement =

    for first 5 seconds distance => ut + 1/2at² = 0 + 1/2 x 5 x 5² = 125/2 = 62.5m

   hence total distance = 500 + 62.5 = 562.5m

d. the  average speed of the entire movement = total distance / total time

      => 562.5/25 = 22.5m