Even though this is from my computer science textbook, I strongly believe this is a question with regards to physics/calculus. I'm not having an issue with using MATLAB but am stuck on interpreting my results which have to do with calculus/physics. When asked to find the time when the balloon hits the ground I come up with 51.1942 hours. This is a problem because the function that determines displacement is only defined on 0 =< t <= 48, as you'll see when you read the question to the problem. Hence, I don't know how to proceed.(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

Let the following polynomial represent the altitude in meters during the first 48 hours following the launch of a weather balloon:

h(t)=-0.12t^4+12t^3-380t^2+4100t+220

Assume that the units of t are hours.

(a) Use MATLAB together with the fact that the velocity is the first derivative of the altitude to determine the equation for the velocity of the balloon.

(b) Use MATLAB together with he fact that acceleration is the derivative of velocity, or the second derivative of the altitude, to determine the equation for the acceleration of the balloon.

(c) Use MATLAB to determine when the balloon hits the ground. Because h(t) is a fourth-order polynomial, there will be four answers. However, only one answer will be physically meaningful.

There are other parts but part C is were I'm having a problem.

2. Relevant equations

3. The attempt at a solution

Code (Text):h=sym('-.12*t^4+12*t^3-380*t^2+4100*t+220');

disp('(a)')

V=diff(h,1)

disp('(b)')

a=diff(h,2)

disp('(c)')

max(double(solve(h)))

(a)

V =

- 0.48*t^3 + 36*t^2 - 760*t + 4100

(b)

a =

- 1.44*t^2 + 72*t - 760

(c)

ans =

51.1942

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# Homework Help: Simple Kinematics

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