A Person in Free Fall Newton's 2nd Law

AI Thread Summary
The discussion focuses on calculating the average acceleration and average force exerted by a parachute during a free fall scenario involving an 80kg aviator. Initially, the aviator reaches a velocity of 60 m/s before opening the parachute, which reduces his speed to 20 m/s after falling an additional 30 meters. The average acceleration can be determined using the change in velocity and the time taken, while the average force exerted by the parachute can be calculated using Newton's second law, F = mass × acceleration. The problem-solving approach involves setting up a quadratic equation to find the time of fall and then using that to solve for acceleration. Overall, the calculations hinge on understanding the relationships between velocity, acceleration, and distance in free fall dynamics.
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A Person in "Free Fall" Newton's 2nd Law

Homework Statement


An 80kg aviator is in free fall and acquires a velocity of 60 m/s and then opens his parachute.
After falling an additional 30m, his velocity has been reduced to 20 m/s. What is the average acceleration of the aviator while his fall is being checked? What is the average force being exerted by the parachute?


Homework Equations


Force = Mass * acceleration
Average acceleration = change in velocity/change in time


The Attempt at a Solution


Any help would be appreciated, Dont understand how to go about problem
 
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If a person has intial speed v_0 and constant acceleration a has, after time t, speed at+ v_0 and will have gone distance (a/2)t^2+ v_0t. So we will fall "an additional 30m" when (a/2)t^2+ 60t= 30. Solve the quadratic equation (a/2)t^2+ 60t- 30= 0for t. Of course, that will depend on a. Put that value of t into at+ 60= 20 and solve that equation for a.
 

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