# Tutor profile: Trenton W.

## Questions

### Subject: MATLAB

Write a Matlab function tickerText(s, iwidth, dt) that displays the string s scrolling through a text window with width iwidth. The parameter dt gives the length of the pause after piece of text is displayed. For example, the following would be displayed scrolling across the command window. tickerText('Sic transit gloria mundi!', 8, 0.1) S Si Sic Sic Sic t Sic tr Sic tra Sic tran ic trans c transi transit transit ransit g ansit gl nsit glo sit glor it glori

function tickerText(s,iwidth,dt) %Trenton Wray textWindow=char(zeros(1,iwidth)); N=length(s); pause(dt); for i=1:1:N+length(textWindow) %conditional to assign value of last char in textWindow if i<=N textWindow(1,length(textWindow))=char(s(i)); elseif i>N %Needed for when s(i) is null textWindow(1,length(textWindow))=' '; end %displays the textWindow and pauses disp(textWindow); pause(dt); %shifts all values in textWindow to the left 1 spot for k=1:1:length(textWindow)-1 textWindow(1,k)=textWindow(1,k+1); end end

### Subject: Calculus

Find y' by implicit differentiation: $$4y^{3}+3x^{2}-y=x^{4}$$

$$4y^{3}+3x^{2}-y=x^{4}$$ $$12y^{2}y{'}+6x-y^{'}=4x^3$$ $$y^{'}(12y^{2}-1)=4x^{3}-6x$$ $$y^{'}=(4x^{3}-6x)/(12y^{2}-1)$$

### Subject: Physics

(Rotational Kinematics) A bike wheel starts at rest and is accelerated at a rate of 4 $$rad/s^{2}$$. What is the angular velocity of the wheel after 10 seconds? What is the angular displacement?

1) List all known variables and variables you want to find. Known: $$W_{0}$$=4 rad/s $$\alpha$$=4 $$rad/s^{2}$$ t=10 s Want to find: W=? $$\theta$$=? 2) Review relevant equations W=$$W_{0}$$+$$\alpha$$t $$\theta$$=$$W_{0}$$+1/2$$\alpha$$$$t^{2}$$ $$W^{2}$$=$$W_{0}^{2}$$+2$$\alpha\theta$$ 3) Find missing variables W=$$W_{0}$$+$$\alpha$$t W=0+4(10) W=40 rad/s $$\theta$$=$$W_{0}$$+1/2$$\alpha$$$$t^{2}$$ $$\theta$$=0+1/2(4)$$10^{2}$$ $$\theta$$=200 rad

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