Question #ab83f

1 Answer
Aug 24, 2016

Let

"East"-> +"ve direction of x-axis"East+ve direction of x-axis

"West"->-"ve direction of x-axis"Westve direction of x-axis

"North"-> +"ve direction of y-axis"North+ve direction of y-axis

"South"->-"ve direction of y-axis"Southve direction of y-axis

vec(V_i)->"Initial velocity vetor"ViInitial velocity vetor

vec(V_f)->"Final velocity vetor"VfFinal velocity vetor

abs(vec(V_i))=8.5m/sVi=8.5ms

abs(vec(V_f))=19m/sVf=19ms

t->"Time of change of velocity"=2stTime of change of velocity=2s

"Direction of "vec(V_i)=S42^@W=(270-42)^@Direction of Vi=S42W=(27042)

"Direction of "vec(V_f)=W35^@N=(180-35)^@Direction of Vf=W35N=(18035)

vec(V_i)=8.5(cos(270-42)hati+sin(270-42)hatj)Vi=8.5(cos(27042)ˆi+sin(27042)ˆj)
=-8.5(sin42hati+cos42hatj)=8.5(sin42ˆi+cos42ˆj)
=-5.69hati-6.32hatjm/s=5.69ˆi6.32ˆjms

vec(V_f)=19(cos(180-35)hati+sin(180-35)hatj)Vf=19(cos(18035)ˆi+sin(18035)ˆj)
=19(-cos35hati+sin35hatj)=19(cos35ˆi+sin35ˆj)
=-15,56hati+10.9hatjm/s=15,56ˆi+10.9ˆjms

"Now average acceleration"Now average acceleration
vec(a)=(vec(V_f)-vec(V_i))/ta=VfVit

=1/2(-9.87hati+17.22hatj)ms^-2=12(9.87ˆi+17.22ˆj)ms2

abs(vec(a))=1/2sqrt(9.87^2+17.22^2)~~19.85ms^-2a=129.872+17.22219.85ms2