Lab3b fluids A

Summary

The video explains an experiment designed to measure the force water can apply using a pivot arm and a balance system. The setup involves adjusting the flow of water from a hose onto a plate, counterbalancing the force with weights to maintain equilibrium. By measuring how long it takes to collect a certain amount of water, students can calculate the force exerted by the water flow. The experiment includes various adjustments to the distance and flow, and the results are used to create a graph for analysis. The process is repeated for accuracy, and detailed instructions are provided.

Takeaways

• 🔍 The experiment focuses on measuring the force that water can apply using a specific setup.
• 💧 A pivot arm with a jockey is used to balance forces and measure the effect of water flow.
• 🔄 A spring provides an upward force to counteract the dead weight of the arm and jockey, achieving equilibrium.
• 🌊 Water is directed from a hose through a nozzle to hit a plate, creating measurable force and movement.
• ⚖️ The system uses a 3:1 moment arm, meaning the applied load will balance with three times the amount of water collected.
• 📏 The diameter of the nozzle (10 mm) and water flow time are used to calculate water velocity.
• ⏱️ The experiment is repeated three times at each position (90 mm, 75 mm, etc.) to ensure consistent results.
• 📊 Based on the time to collect water, students can calculate the force applied by the water and plot a graph.
• 📐 The graph should be drawn in portrait mode, showing a line of best fit rather than connecting individual data points.
• 💡 Students are expected to analyze flow rates, adjust for different positions, and compute the applied forces.

Q & A

What is the main focus of experiment 3B?

The main focus of experiment 3B is to measure the force that water can apply by using a setup involving a pivot arm and a jockey to balance the force.

How does the jockey system work in the experiment?

The jockey system is positioned on a pivot arm, and its center of mass is aligned at zero. The system is adjusted using a spring to balance the forces and achieve equilibrium, allowing the force of the water to be measured.

What role does the spring play in the setup?

The spring provides an upward force to counteract the downward force of the jockey and the beam's dead weight, ensuring the system is in equilibrium.

How is water flow used to adjust the system during the experiment?

Water flow from a submersible pump hits a plate attached to the pivot arm, and the force from the water helps to balance the system. The flow rate is adjusted so that the jockey returns to its equilibrium position.

What is the purpose of the bucket and plunger system?

The bucket and plunger system is used to capture water in the experiment. When the arm is raised, the plunger closes the hole in the bucket, allowing water to collect. When the arm lowers, the plunger opens, and the water flows out, allowing measurements of water weight and force.

What is the significance of the 90mm, 75mm, and other distances mentioned in the experiment?

These distances represent the position of the jockey along the pivot arm. The further out the jockey is positioned (e.g., at 90mm), the more force is required to balance it, and vice versa for shorter distances like 75mm.

Why is the water flow rate adjusted at different jockey positions?

The water flow rate is adjusted because different jockey positions create different moments. When the jockey is positioned closer, less force is needed to balance the system, requiring a lower water flow rate.

How is the velocity of the water calculated?

The velocity of the water is calculated using the flow time, the diameter of the nozzle (10mm), and the formula for cross-sectional area (Pi d²/4).

Why is the experiment repeated three times at each position?

The experiment is repeated three times at each position to ensure consistency and accuracy in the readings, especially for the times taken to capture 18kg of water.

What is expected from the graph that is drawn at the end of the experiment?

The graph should plot the force values calculated from the experiment and follow a line of best fit, not point-to-point, with the axes set according to the provided spreadsheet. The graph should be in portrait orientation.