Question

2. Car A, moving in a straight line at a constant speed of 20. meters per second, is initially 200 meters

behind car B, moving in the same straight line at a constant speed of 15 meters per second. How far
must car A travel from this initial position before it catches up with car B?
A) 800 m
B) 200 m
C) 1000 m
D) 400 m

Answer 1

Step-by-step explanation:

Given:

V₁ = 20 m/s

ΔS = 200 m

V₂ = 15 m/s

___________

S - ?

Car motion equation:

X₁ = V₁*t = 25*t

X₂ = ΔS + V₂*t = 200 + 15*t

Since the second car overtook the first, then:

X₁ = X₂

25*t = 200 + 15*t

5*t = 200

t = 200 / 5 = 40 с

Distance:

S = ΔS + V₂*t = 200 + 15*40 = 200 + 600 = 800 m

Correct answer:

A) 800 m