Thank you for the opportunity to help you with your question!

0km/hr means the person would be STOPPED in mid-air since zero speed means no movement. Terminal speed is the maximum speed an object attains when the drag force through the air equals the gravitational force thereby creating zero acceleration resulting in a constant speed.

Please let me know if you need any clarification. I'm always happy to answer your questions.

ok. But the question is a multiple choice and the three other choices are 15km/h, 150km/h, & 1500km/h. Which one is correct and why? Is there a rule or a formula that I should know?

There's a formula for terminal velocity where the speed is directly proportional to the weight of the falling object and inversely proportional the area of the chute.

Jun 14th, 2015

I would say the answer is probably 15km/hr because the speed of a sky diver in free fall without opening his parachute is about 195km/hr. So, when the chute opens the speed is reduced greatly and 15km/hr is the only reasonable choice among the options given.

Jun 14th, 2015

And if you think about it, the other speeds are so fast it would KILL the person when he hits the ground!