I am a physics question please.

Question

What if anything is wrong with the sketch here and why?

I cannot actually put the sketch here but it is a sketch of line X going to the right and line y crossing with X on the left moving the arrow in a vertical line upwards.

Line y shows a bullet to the right of the line moving from right to left with -1/2mv^2 and x with the bullet above line x on the right side moving from left to right with 1/2mv^2.

Thanks!!

Answer 1

1/2mv^2 is kinetic energy. You have shown that energy from right to left is negative.

May be you are thinking that left to right is taken as positive. So, right to left should be negative.

But note that energy is a scalar, not a vector. Therefore, it should be 1/2mv^2 and not -1/2mv^2

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