1. The problem statement, all variables and given/known data a planet with radius of 12km spins at 520revs/s find: a) avg speed of a point on the planets equator over 2.5 of a revolution b)find avg acceleration on stars circumfrance over 3/4 of a rev c)find distance covered by point on the equator in 1 second d) find displaement f=520rev/s r=12000m 2. Relevant equations fc=mv^2/r T=1/f v=2piR/T 3. The attempt at a solution a) if i construct a vector triangle using v1 and v2 at the beginning of 3/2 of a rev and at the end, i can believe i can solve for vavg this way making a triangle where Vavg opposes the angle of 144 degrees... v=2piR/T where T=1/f so i get v=2Pi*Rf i considered V1and V2 = v vavg^2 = 2(2Pi*R*f)^2-2(2Pi*R)^2cos144 is this okay? b)m*ac=mv^2/R where ac = centripetal accell and v = 2pi*R*F ac = ((2pi*R)*f)^2/R c)m*ac= (d/t)^2/R if t=1s d=√(R*ac) d)... i think i may have solved displacement above.. perhaps i am confusing the distance and displacement.