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Mechanics

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Size:  491.2 KBI'm really struggling with mechanics in general and can't do this exercise. I got the first part of 6 correct with 23.83 but then for the second part I did 4=4-(2.75xt) giving t as 3.2 which was wrong so help there please.

    For 7 I did 80^2/2x1000 which was 3.2 and correct

    For 8 I used v=0+1.5x8=12 then t=v-u/a and got 12 but this is wrong so help please

    For 9 I did v=0+(10x0.625)= 6.25 then using s=vt-1/2at^2 so (6.25x10)-1/2x0.625x10^2=31.25 which was wrong

    I couldn't do 10 or 11 at all.

    Please help me with all of these
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    Anyone?
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    For 6ii) you have averaged the acceleration however the time spent in each acceleration phase is different (not 50/50) so you can't do this.

    use v=u+at for each acceleration phase separately then add them.


    For 8 you need to consider
    it going up the slope when accelerating
    going up the slope whilst decelerating
    going down the slop back to the start.
 
 
 
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