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

1 Answer
Jan 10, 2018

The rate of acceleration is =3.01ms^-2 in the direction =266.6^@ anticlockwise from the "x-axis"

Explanation:

The acceleration is the derivative of the velocity.

v(t)=(tsin(pi/3t), 2cos(pi/2t)-3t)

Therefore,

a(t)=v'(t)=(sin(pi/3t)+pi/3tcos(pi/3t), -pisin(pi/2t)-3)

When t=2

The acceleration is

a(2)=v'(2)=(sin(pi/3*2)+pi/3*2*cos(pi/3*2), -pisin(pi/2*2)-3)

a(2)=(sqrt3/2-pi/3, -3)=(-0.18,-3)

The rate of acceleration is

=||a(2)||=sqrt((-0.18)^2+(-3)^2)=3.01ms^-2

The direction is theta=180+arctan (3/0.18)=266.6^@ anticlockwise from the "x-axis"