An object's two dimensional velocity is given by v(t) = ( t^2 +2t , 2cospit - t ). What is the object's rate and direction of acceleration at t=3 ?

1 Answer
Jan 25, 2017

Magnitude is 15.8115 and direction is (-18.435^@)

Explanation:

As v(t)=(t^2+2t,2cospit-t),

at t=3, v(3)=(3^2+2xx3,2cos3pi-3)

= (9+6,2xx(-1)-3) = (15,-5)

Hence object's rate is |v(3)|=sqrt(15^2+5^2)

= sqrt250=5sqrt10=5xx3.1623=15.8115

and direction is given by tan^(-1)((-5)/15)=tan^(-1)((-1)/3)=-18.435^@
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