2.3b Freefall in Two Directions (1D) | AS Kinematics | Cambridge A Level Physics

[@durkhanayjan7300]

why is the line on the graph starting from a different velocity rather than zero when the ball is thrown upwards? shouldnt it start from 0?

[@JaveriaYousuf]

It's due to the force that was applied on the ball in order to throw the ball upwards that gave the ball a certain initial velocity.

[@MEDICO-fd7jo]

Thank you

[@yasminema4733]

why is it -9.81 the whole time if I put the upwards direction as positive?

[@itiswatitis821]

gravity going downwards

[@a.meforyou]

Because the object is slowing down to 0 ms-¹. So its decelerating.

[@danielxoxo.]

At 18:28, you don't need to use all that the teacher used, simply use s=vt-1/2 at^2 after you get the answer, multiply by 2.

[@mr-bean2306]

18:30 Why dont you directly use s=vt-1/2at² U substituted equation?

[@ETphysics]

t and u are both not known at the beginning right?

[@the21podcast]

@@ETphysics but u is not even used in the equation. i tried that other equation and the answer came out to be the same

[@amazkhawar3657]

22:00

[@mcneelynorman1]

@@the21podcast Correct. In the beginning she took positive to be in the upward direction but if you make the downward direction positive then you massively simplify the calculations. By making downward positive you do have a "u" value.

[@amnah1892]

i need U toooooo miss

[@loliking6628]

youre so cute bro

[@the21podcast]

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[@danielxoxo.]

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