PLEASE HELP 50 POINTS 9TH GRADE PHISICS ANYONE FROM K12 OR IF YOU HAVE DONE THIS PROJECT CAN YOU HELP ME WITH THE SECOND PART ON PULLEYS PLEASE HELP.

Which best represents the law of conservation of mass ?

Aparticle moves in the xy plane with constant acceleration. at time zero, the particle is at x = 6 m, y = 8.5 m, and has velocity ~vo = (9 m/s) ˆı + (−2.5 m/s) ˆ . the acceleration is given by ~a = (4.5 m/s 2 ) ˆı + (3 m/s 2 ) ˆ . what is the x component of velocity after 3.5 s? answer in units of m/s.

An isotope undergoes radioactive decay by emitting radiation that has a –1 charge. what other characteristic does the radiation have?