Answer:
8N and 32N
Step-by-step explanation:
Given that a light board, 10 m long, is supported by two sawhorses, one at one edge of the board and a second at the midpoint. A small 40-N weight is placed between the two sawhorses, 3.0 m from the edge and 2.0 m from the center.
To calculate the forces that are exerted by the sawhorses on the board, we must consider the equilibrium of forces acting on the board.
Let the two upward forces produce by the saw horses be P1 and P2
Assuming that the weight is negligible
Sum of the upward forces = sum of the downward forces.
P1 + P2 = 40 ....... (1)
Also, the sum of the clockwise moment = sum of the anticlockwise moments.
Let's assume that the board is uniform. The weight will act at the centre.
Taking moment at the centre:
P1 × 5 + 40 × 2 = 0
P1 = 40 / 5
P1 = 8N
Substitute P1 into equation 1
8 + P2 = 40
P2 = 40 - 8
P2 = 32N