Askier leaves a ski jump with a horizontal velocity of 29.4 m/s. the instant before she lands three seconds later, the magnitudes of the horizontal and vertical components of her velocity are:

The horizontal and vertical velocity of the skier are both 29.4 m/s.

Explanation:

If no forces are acting in the horizontal direction, then the horizontal component of the velocity remains constant in time:

Vx = 29.4 m/s

For the vertical component the gravity acceleration must be considered, and the vertical velocity can be written as:

Vy = g*t

Here the value for g is 9,8 m/s2. Note that the initial vertical velocity is zero.  

Evaluating in the velocity’s expressions for a time of 3 seconds we obtain:

Vx = 29.4 m/s

Vy = 9.8 m/s2 * 3 s = 29.4 m/s