The speed is constant since there is no opposite force facing the car
That’s my best guest hope it helps !! :)
Answer c, velocity would be the answer.
The speed of sound depends on the medium in which it is transported.
Sound travels fastest through solids, slower through liquids and slowest through gases.
So it will travel slowest through water at 55 degrees
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A)Ep'=mgh=mgl(1-cosa).At the bottom of the swing Ep=0(reference level),so the potential energy as the child is just released is bigger than the potential energy at the bottom of the swing.;B)The speed of the child at the bottom of the swing-->v=√(2gh)=√[2gl(1-cosa)];C)I don't think that the tension does any work.