If the track is 10km long, and X travels at 40 km/h, it will take 1 hour to do 4 laps. this means that car X will do one lap in 15 minutes. Y travels at 30 km/h, which means it will do 3 laps in 1 hour, meaning that car X will do 1 lap in 20 minutes.
X- 15, 30, 45, 60
Y-20, 40, 60
Therefore, after an hour, they will pass again.
The formula for displacement is:
<span>d=1/2(v0+v)t
If we multiply by 2/t we will have
2*d/t = v0+v
In order to find v0 we subtract </span><span>v (the final velocity)
2*d/t - v = v0
The final result is that: v0 = </span>2*d/t - v
1. ABC
2. B
That’s the answer
Yes, -9 can be written as a fraction over 1, meaning it is a rational number
