An object's two dimensional velocity is given by v(t) = (3t-sqrtt , t^3- 3t ). What is the object's rate and direction of acceleration at t=5 ?

1 Answer
Apr 27, 2017

The rate of acceleration is =4ms^-2 in the direction of =73.6º

Explanation:

Acceleration is the derivative of the velocity

a(t)=v'(t)

v(t)=(3t-sqrtt,t^3-3t)

a(t)=v'(t)=(3-1/(2sqrtt),3t^2-3)

When t=2,

a(2)=(2.65,9)

The rate of acceleration is

||a(2)||=sqrt((2.65)^2+9^2)

=sqrt16=4

The direction is

in the first quadrant

theta=arctan(9/2.65)=73.6º