What is meant by Direction of Shm?Someone plz explain.
Also in the iit carnival test one question was->
A particle moves in space such that its position at any time t (in seconds) is given by :

where x, y, z are in metres.
The normal component of the acceleration of the particle at t = 2 s has the magnitude?
How to get the answer?
My answer 169/7 was wrong.