Final answer:
Atmospheric pressure does not contribute to a net force on a dam because it acts equally on opposing surfaces. The force a dam must withstand comes from the water pressure depending on the reservoir's depth and width.
The answer is b) No, atmospheric pressure does not contribute to a net force on the dam.
Step-by-step explanation:
Is there a net force on a dam due to atmospheric pressure? The answer is b) No, atmospheric pressure does not contribute to a net force on the dam.
Atmospheric pressure acts equally on all surfaces exposed to the air, including both the water surface behind the dam and the air side of the dam.
This equal application of pressure on opposing surfaces means there is no net atmospheric pressure acting on the dam. However, the force that a dam must withstand is primarily due to the water pressure created by the depth and width of the water reservoir; it is this water pressure that creates a force against the dam, not the atmospheric pressure.