(1) A particle move along the x axis, as (SI unit). (a) The functions of its velocity and accelerator vector against time； (10 marks ) (b) Its average velocity in the first 3 seconds. (10 marks )

My answer is opptionc, just check with anyone else

Answerthe distance between the two ends of the galaxy is 150,000 light years;

Decrease the surface area of the object and also decrease the concentration which will allow the particles to collide faster

Repeated trials allow you to calculate a mean which can reduce the effect of random errors to make your results more precise.your results will also be reproducible therefore if someone else did the same experiment they'd get the same results which would make your results more reliable.