Final answer:
To find an unknown mass in an Atwood machine, measure the acceleration of a known mass and use the principles of physics to compute the unknown mass.
Step-by-step explanation:
To determine the unknown mass in an Atwood machine, you need another mass whose value is known, a stopwatch, and possibly a meter stick, knowing that the pulley system is frictionless and the string mass is negligible. Firstly, attach the known and unknown masses to either end of the string, making sure the string goes over the pulley.
- Release the system so that the weights are free to accelerate, and use the stopwatch to measure the time it takes for the known weight to hit the ground.
- Measure the distance traveled by the known weight before it hits the ground, which, combined with the time measured, will give you the acceleration of the system.
- Next, use the equations of motion and the concept of torque to calculate the tension in the string.
- Finally, apply Newton's second law of motion to solve for the unknown mass. The tension and the acceleration, which have been calculated, would allow you to determine the unknown mass.
This experimental procedure, when followed accurately, will yield the mass of the unknown object without the need for direct measurement with scales.