Question

R = (2+2+1) i - (t+1)] + t3 k what is the direction of initial velocity

Answer 1

Answer:

In the - j direction, that is negative of the y-axis

Explanation:

As typed in the question, the position of the object is given by the expression in three component ( i, j, k) form:

r (t) = 5  i  - (t + 1 )  j  + t^3  k

and since the velocity is the derivative of position with respect to time, by doing the derivative of this expression we get:

v(t) = 0  i  -  1  j   +3 t^2  k

which for the initial velocity requested (that is at time zero) we have:

v(t) = 0  i  -  1  j   +3 (0)^2  k = = 1  j

Then the direction of the initial velocity is entirely in the direction of the j versor, that is pointing to the negative of the y-axis.