Question

Need someone to check my work and answers:
At the instant the traffic light turns green, a car that has been waiting at an intersection starts ahead with a constant acceleration of 2.80 m/s2. At the same instant a truck, traveling with a constant speed of 20.0 m/s, overtakes and passes the car.

(a) How far beyond its starting point does the car overtake the truck?
20t = 1.40t²
cancel "t"
1.40t = 20
t = 20/1.4 = 14.3s
distance at overtake = 20(14.3) = 286 m ANS-1
(b) How fast is the car traveling when it overtakes the truck?
auto's speed at any time = t is
V = 2.80t = 2.80(14.3) = 40 m/s m/s ANS-2
-For part (c) and (d) of the question, can you explain how the graph for both parts would look like and how you got it.
(c)Draw the correct x−t graph of the motion of both vehicles.
(d)Draw the correct vx−t graph of the motion of both vehicles.

Answer 1

looks good...except for the word "cancel t" in (a). variables cannot "cancel" out, what you did was divide each side by t to reduce it to 1.40t=20