If you happen to be trapped inside a burning building and need to jump out the window, should you propel yourself upward first or just let yourself fall? Do not perform any calculations. Explain your answer
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Let's assume we start downward with the initial vertical speed Uy = 0. So if we just roll off the roof top at h, we will accelerate over h at a bit under g = 9.8 m/s^2. But if we first jump upward, when we reach Uy = 0 after rising a bit, we'll be falling from H > h and still accelerating at the same g.
And there you are. Take it on faith that when you fall and accelerate at the same rate from H, you'll smack into the cement below at a faster speed than if you fall from h < H. And that higher impact smack comes from accelerating a bit longer from H than from h.
ANS. Just let yourself fall...you'll still smash your brains all over the sidewalk but the rescue people can scrape them up from a smaller splatter area than from the higher jump.
And there you are. Take it on faith that when you fall and accelerate at the same rate from H, you'll smack into the cement below at a faster speed than if you fall from h < H. And that higher impact smack comes from accelerating a bit longer from H than from h.
ANS. Just let yourself fall...you'll still smash your brains all over the sidewalk but the rescue people can scrape them up from a smaller splatter area than from the higher jump.
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Let yourself fall.
Whatever initial upward velocity you provide will be added to your downward velocity at impact.
Vf = √[Vi² +2gh]
Whatever initial upward velocity you provide will be added to your downward velocity at impact.
Vf = √[Vi² +2gh]