Suggested Answer
Answer:Step-by-step explanation:Given informationu=initial velocity=20m/ss=distance travelled=40mv=final velocity=0m/s (the car stopped after traveling 40 m)To find a = acceleration of the car and its directionWe know that the equation for uniform motion is v^2=u^2+2astherefore by rearranging we geta= [tex](v^2 - u^2)/ 2s[/tex]putting the values we geta= (0 - [tex]20^{2}[/tex] )/ [tex]/ 2*40[/tex]a= -400/80a=-5 [tex]m/s^2[/tex]here negative sign before 5 indicates that the acceleration direction was opposite the car's motion, hence stopping it eventually.And the magnitude of the acceleration is 5[tex]m/s^2[/tex]