If a board spans two bricks and carries a load of 10kg, where on the board does tension occur?
The area of a span that is unaffected by an applied force is
the bottom of the board is in tension, the top in compression
the second question does not mean anything to me (not stressed maybe?)
Do your own work!
In order to determine where tension occurs on the board, we need to consider the forces and the conditions of equilibrium. Let's break down the problem step by step:
1. Identify the forces: The board is carrying a load of 10kg, which means there is a downward force acting on the board due to gravity. This force, known as the weight, can be calculated using the formula weight = mass × acceleration due to gravity. Assuming the acceleration due to gravity is approximately 9.8 m/s², the weight of the load can be found as weight = 10kg × 9.8 m/s² = 98N.
2. Determine the reaction forces: Since the board is resting on two bricks, there will be two reaction forces acting on the board, one at each end where it is supported. These reaction forces keep the board in equilibrium. Let's call these reaction forces R1 and R2.
3. Apply the conditions of equilibrium: For an object to be in equilibrium, the net force acting on it must be zero, and the sum of the torques (rotational forces) must also be zero. In this case, as there is no horizontal acceleration, the net force in the horizontal direction is zero.
4. Analyze the torques: To determine where the tension occurs, we need to look at the torques acting on the board. Torque is calculated as force × perpendicular distance from the pivot point (fulcrum). In this case, the fulcrum is the point of contact between the board and the two bricks.
Since the board spans two bricks evenly, the perpendicular distance from the pivot point to each end of the board is equal. Therefore, the torques created by the reaction forces R1 and R2 will cancel each other out, resulting in no net torque on the board.
5. Conclusion: Based on the analysis, tension does not occur on the board. The board is in equilibrium with the load, and the reaction forces at each end of the board counterbalance the weight of the load, ensuring no tension or bending forces are present.