The force P is the weight component parallel to the slope and Q is the weight component perpendicular to it. To travel at a constant velocity down the slope, the net force in the direction of motion must be zero, requiring opposing forces to balance gravity.
The forces labelled P and Q in the scenario of a person skiing down a slope are the components of the skier's weight relative to the slope. The force P is the component of the weight parallel to the slope, and Q is the component perpendicular to the slope. With an angle of 35 degrees and the weight being 850 N, we can calculate P and Q using trigonometric functions
P (parallel component) = w × sin(θ), which equals 850 N × sin(35 degrees).
Q (perpendicular component) = w × cos(θ), which equals 850 N × cos(35 degrees).
For the skier to be traveling at a constant velocity, the condition necessary is that the net force in the direction of motion (down the slope) must be zero. This means that any forces acting down the slope, such as gravity, must be balanced by opposing forces, such as friction or air resistance. However, since it is given that there is no friction between the ski and the snow, the skier would either continue in motion if already in motion or would start accelerating if at rest.