Answer:
Twice
Explanation:
Use constant acceleration equation:
x = x₀ + v₀ t + ½ at²
where x is the final position,
x₀ is the initial position,
v₀ is the initial velocity,
a is the acceleration,
and t is time.
The position of the car is:
x = (84) + (0) t + ½ (2) t²
x = 84 + t²
The position of the motorcycle is:
x = (0) + (20) t + ½ (0) t²
x = 20t
When the positions are equal:
84 + t² = 20t
t² − 20t + 84 = 0
(t − 6) (t − 14) = 0
t = 6 or 14
The vehicles meet twice, once after 6 seconds, and once after 14 seconds.
