Given: A student weighing W = 120 lb rides a skateboard with the trucks (the part the wheels are mounted to) L = 32 inches apart. Assume that her feet are positioned inward of the wheels at equal distance of L/4, and she applies half of her weight at each point. Assume the board is simply supported.

Req'd: Determine the reaction force at the front truck R_{A}.

Sol'n: The FBD of the skateboard is first drawn. The reaction force at A can be calculated by setting the sum of the moments acting about B to zero: