Guys This Is A Doubt Regarding Calculus...we Know That Speed = Distance / Time And Acceleration = Speed / Time... Then Putting Acc As 9.81 And Time As 1.7 And Solving For Distance We Get 28.3509 Instead Of 14.17... Is The Mistake?

[Sachin114]

we know that speed = distance / time and acceleration = speed / time... then putting acc as 9.81 and time as 1.7 and solving for distance we get 28.3509 instead of 14.17... where is the mistake? Thank you

[fiction-factory]

distance = ut + 0.5 a t²
What is your u value?

[fiction-factory]

accelareration is not velocity/time- it's change in velocity over time

[fiction-factory]

acceleration

[Calibax]

x=ut+ 1/2 a t^2
= 0 + 9.81 x(1.7 x1.7) = 28.3509

[fiction-factory]

you need to divide that by 2 Calibax

[Calibax]

Oops forgot the 1/2

x=ut+ 1/2 a t^2
= 0 + 9.81 x 0.5(1.7 x1.7) = 14.175

[Calibax]

Thanks FF. It's been a long time since I did O level physics. I'll leave you to it :o)

[fiction-factory]

Easily done Calibax. I should keep a calculator and pen and paper close by. When we did O level physics s stood for distance. Now s stands for speed (a term we were told not to use) at GCSE so I have to stop and think

[Old_Geezer]

Did 50% of it have to go in the title ?
One can cut & paste into the right box.
Makes it less easy to take in.

[Old_Geezer]

ok having pushed on it's not 50% but almost duplicated.
Told you it wasn't as easy to take in.

[Sachin114]

The initial speed is 0. Actulky i know the that the right ans is 14 by the equat of kinetic... but why does it not give right ans by using speed and acceleration formula seperately

[Old_Geezer]

Because your definition of acceleration was incorrect ?
It's the rate of change of velocity per unit of time rather than velocity divided by time.

[fiction-factory]

Effectively you need the average velocity. In this case I assume it starts at 0 and ends up at whatever it is.

[fiction-factory]

v= u +at and in your case if u=0 then v= 9.81 x 1.7= 16.667
Then use another equation to find s
Still gives 14.17

[fiction-factory]

Calculus is all about the rate of change.

[Sachin114]

Thank you guys