Two dogs are standing 960 m apart from each other. The first dog runs at a speed of 9 m/s and the second runs at 7 m/s. If two dogs run towards each other, after how much time will they bump into each other?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 60 s
When two bodies move towards each other, the gap between them closes at the sum of their speeds (the relative speed), so the time to meet is the gap divided by that sum.
Relative speed \(=9+7=16\) m/s, so the gap shrinks by 16 m every second
Time to meet \(\displaystyle =\frac{960}{16}=60\) s