Two planes approach each other head-on. Each has a speed of 760 km/h , and they spot each other when they are initially 13.5 km apart.
Answers (1)
Closing speed is 1530 km/h.
T = 13.5km x h/1530 km Notice that I inverted the speed to make the fractions cancel and leave "h" in the answer. After all if speed = 1530km/h then 1/speed = h/1530km. Study that concept until it seems obvious. It is a basic assumption in physics.
T = 13.5km x h/1530 km = 0.008823529 h = 31.76 seconds
If that seems very short, it's because 1530 km/h is just under 950 miles per hour.