An object's two dimensional velocity is given by v(t) = ( sqrt(t^2-1)-2t , t^2). What is the object's rate and direction of acceleration at t=2 ?

1 Answer
Apr 23, 2016

vec a=-0,85 hati+4 hatj
theta=-78^o

Explanation:

vec a(t)=vec a hat i+ vec a hat j

vec a(t)=d/(d t)(sqrt(t^2-1)-2t)hat i+d/(d t)(t^2)hat j

vec a(t)=((2t)/(2*sqrt(t^2-1))-2)hat i+(2t)hat j

vec a(2)=((2*2)/(2*sqrt(2^2-1))-2)hat i+(2*2)hat j

vec a(2)=(2/sqrt3-2)hat i+4hatj

vec a(2)=((2-2sqrt3)/sqrt3)hat i+4 hatj

vec a=((2sqrt3-6)/3)hati+4 hatj

vec a=-0,85 hati+4 hatj

||vec a ||=sqrt((-0,85)^2+4^2)" magnitude of a"

a=4,09 " "("unit")/s^2

tan theta=4/(-0,85)

theta=-78^o