do i use this formula h=0.5gt² ?
Given height is 9144mm (30,000ft) Given weight is 60kg
how do I find the speed of falling? and time taken to reach the ground.
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Do you know Newton's second law? – Mhenni Benghorbal Apr 30 '14 at 03:40
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If i know i wont be here right? – BeyondProgrammer Apr 30 '14 at 03:41
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1What course is this? – Mhenni Benghorbal Apr 30 '14 at 03:44
3 Answers
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Your formula is correct assuming 1) you start at $h=0, t=0$ 2)you start at rest 3)$h$ is measured downwards. Usually $h$ is measured upwards, so there should be a minus sign. In that case you just set $h=9144$ and solve for $t$.
Ross Millikan
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Is a example of free fall, in this the equation of movement is given by: $$h(t)=h(0)-\frac{1}{2}gt^2$$ When $h(0)$ is the height. And the velocity is given by: $$v(t)=-gt$$
So if you need to know when $h(t)=0$ to find the time and then replace in the equation of the velocity to find your result.
But there is a one tricky equation!
$$v^2(t)=-2g(h(t)-h(0))$$
Which make all more easy
rlartiga
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