# An object's two dimensional velocity is given by #v(t) = ( cost , -t^3 +4t )#. What is the object's rate and direction of acceleration at #t=3 #?

##### 2 Answers

The rate of acceleration is

#### Explanation:

The acceleration is the derivative of the velocity

When

The rate of acceleration is

The direction is

#### Explanation:

As two dimensional velocity of object is given by

accelaration is given by

and at

or

and its magnitude is

and direction is