1. The problem statement, all variables and given/known data A boy on a board B slides down a slope. The angle of the slope to the horizontal is 30°. The total resistive force F acting on B is constant. The boy on the board B moves with velocity v down the slope. The variation with time t of v is shown in Fig. 3.2. Calculate the resistive force. 2. Relevant equations wsinA----? 3. The attempt at a solution Resistive force= WsinA = 75 x 9.81 x 0.5 = 367.5 N My answer does not match with the correct answer. How do you solve this? Thanks!