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# M2 Projectiles Mark Scheme watch

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1. Hiya
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I am starting to try and understand M2 by doing questions, so be prepared in seeing a massive influx of threads from me where I'm stuck

I have done part a) to find the angle to be 22.54, which the mark scheme says is correct

For part b) I am finding the total time taken and have made a quadratic and have used the quadratic formula or find 2 values of t, being (2sqrt30)/7 and -4.69
I assumed the positive value to be correct, but the mark scheme has the positive version of my negative value and says that's correct.

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What am I doing wrong?
2. (Original post by KaylaB)

What am I doing wrong?
Just solving it wrong. How are you solving it? Using a calculator? Check if you have entered it correctly. Your quadratic is perfect, but I get and as solutions.

So you can be safely assured that your mechanics is correct, but you're just making a silly error somewhere whilst solving or inputting the quadratic into a calculator.
3. (Original post by Zacken)
Just solving it wrong. How are you solving it? Using a calculator? Check if you have entered it correctly. Your quadratic is perfect, but I get and as solutions.

So you can be safely assured that your mechanics is correct, but you're just making a silly error somewhere whilst solving or inputting the quadratic into a calculator.
Yeah I was using a calculator, and I found my problem, I was using b = 40sin22.54 instead of b = -40sin22.54
So that solves that thanks
4. (Original post by KaylaB)
Yeah I was using a calculator, and I found my problem, I was using b = 40sin22.54 instead of b = -40sin22.54
So that solves that thanks
Yay!

5. (Original post by Zacken)
Yay!

6. (Original post by KaylaB)
Figures.

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