## Homework 7

### Re: Homework 7

F11Jonathan wrote:Will HW7 be postponed because we haven't gone over the Newton-Raphson method yet? We need to use it for the MATLAB assignment and homework problems 3.5.4, 3.5.5, and 3.5.6.

No, it won't be postponed - we'll cover Newton-Raphson on Tu.

It's pretty straightforward.

Dan

### Re: Homework 7

Is the correct approach to Problems 3.5.4, 3.5.5 and 3.5.6 to find the velocity and acceleration equations (phi, phi_q, nu, gamma) and then use Newton's method in Matlab to solve for positions, then velocities, then accelerations at the given time point?

### Re: Homework 7

F11Wendy wrote:Is the correct approach to Problems 3.5.4, 3.5.5 and 3.5.6 to find the velocity and acceleration equations (phi, phi_q, nu, gamma) and then use Newton's method in Matlab to solve for positions, then velocities, then accelerations at the given time point?

Yes, that's the idea: formulate Phi, Phi_q, nu, gamma for these problems. Then, only at *one* point in time, compute positions, then velocities, then accelerations. You can use MATLAB to that end, but equally good, you can use pen and paper since the problems are relatively small and you only have to do this for one value of time t. Consider 3.5.4, for instance. Take t=0.25. Find at that time *only* what the position of the mechanism is (you might use Newton-Raphson in MATLAB but might be able to figure out the solution by just looking at the system). Then find what the velocity of the mechanism is (take a time derivative of Phi(q,t), get nu and then solve a 3X3 linear system). The same for acceleration (take two time derivatives of Phi(q,t), produce gamma, solve a 3X3 linear system and get qddot).

Post follow up questions if this is still confusing.

Dan

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