Vertical motion and qudaratic equation questions

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The discussion revolves around calculating the height of a cricket ball thrown vertically at an initial speed of 20 meters per second after one second. Participants mention using the formula for vertical motion, specifically -4.9t^2 - ut, where 'u' represents the initial velocity and 't' the time. There is some confusion regarding the correct substitution of values and the interpretation of the variables involved. The importance of clearly stating the formula before solving is emphasized to ensure understanding of the problem. Overall, the focus is on applying the quadratic equation to determine the ball's height accurately.
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1. a cricket ball is thrown at 20 metres per second . how high will it be after 1 second?

I will subtitute the values in -4.9x1^2 - 20-1



2. any way the formula is -4.9t^2 - ut



3. I think the answer is -4.9-21 :confused:

Sorry for hurry, it is due tomorrow
 
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jmathew13 said:
1. a cricket ball is thrown at 20 metres per second . how high will it be after 1 second?

I will subtitute the values in -4.9x1^2 - 20-1



2. any way the formula is -4.9t^2 - ut



3. I think the answer is -4.9-21 :confused:

Sorry for hurry, it is due tomorrow


Thrown in what direction? ut is not the same as u-t, either
 
sorry then it is -20 so do u know who to do it?/:confused:
the question says it is vertical motion so it should be thrwon vertically
 
Last edited:
jmathew13 said:
1. a cricket ball is thrown at 20 metres per second . how high will it be after 1 second?

I will subtitute the values in -4.9x1^2 - 20-1



2. any way the formula is -4.9t^2 - ut



3. I think the answer is -4.9-21 :confused:

Sorry for hurry, it is due tomorrow


All the equations you have, involve 4 of the following
u,v,s,a,t [some people use d instead of s].
You could start by listing the values for the ones you know, and identifying the one you want, then chose the formula involving those variable, then carefully solve.

Your solution should always start with the formula written out, just to show that you know what you are trying to do.
 
Vertically upwards (probably, given the wording of the question, but I am still not sure), or vertically downwards?

You have initial velocity, time and acceleration. What formula(s) do you know that can link this to position?
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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