1. The problem statement, all variables and given/known data This is the question. As an appreciation for his excellent contributions towards making Universiti Sains Malaysia an APEX university, Bala is given the opportunity to do an experiment at the Stanford particle accelerator, USA. During one of his experiments, he detected the creation of an particle. From his calculation, the particle has a rest energy 1672 MeV and total energy 2330 MeV. (a) He wonders: is the particle a particle without mass? Help him by explaining your answer. (b) If the particle decays and leaves a track 24 mm long, what is the (i) speed of the particle while making the imprint on the track? (ii) momentum of the particle? (c) He wrote a note in his laboratory book: mean lifetime of particle = 8.2 x 1011 s Is this value correct? Justify your answer. 2. Relevant equations This is the formula that i thought E = mc2 E = (1/2)mu p = mu v = d/t a = v/t 3. The attempt at a solution i've 1st and 2nd attempt at this cases. For question 1)b)i) -- get the Ekinetic with Etotal = Erest + Ekinetic -- then, get the mass using E=mc2. -- then, i get the velocity using Ekinetic = (1/2)mv -- then, i get the time using v = d/t. -- the data is : Ekinetic = 658 MeV, Mass =7.31 x 10 power of -17 g, V = 1.8 x 10 power of 17 m/s, t = 1.33 x 10 power of -19 s. -- lastly using the a = v/t is 1.35 x 10 power of 36 m/s for 1)b)ii) using the p=mu i get the momentum 13.158 for 1)c) lifetime using lifetime = P/triangle(t) = then using smooth T = 1/r i get 1.33 x 10 power of -19s. LASTLY, i think this is not the best solution for the question, i think i miss something? i wonder if my answer right or wrong/// anybody please>>>?