A car starts from rest and moves along the positive x-axis with a constant acceleration of 5 m/s/s for 8 seconds. It then continues with constant velocity, i. e. the velocity it attains at 8 seconds for the next 5 seconds. What will be the distance covered by the car in the first 12 seconds of its motion?

340

Explanation:

Because you are moving at 5 m/s^2 for 8 seconds, you need to do some arithmetic to get the distance covered in the beginning. TO do this, you do 5 + 5*2 + 5*3 + 5*4 + 5*5 + 5*6 + 5*7 + 5*8, and once you have passed eight seconds, you need 4 more seconds with constant velocity, or 4(5*8). Your final equation would be 5+10+15+20+25+30+35+40+40+40+40+40. Hope this helps!

it is a negative acceleration