Understanding the Setup
* Pulley: A pulley changes the direction of the force but doesn't change its magnitude.
* Frictionless: This means we don't have to consider any energy loss due to friction.
* Negligible Mass: The string has almost no mass, so we don't need to account for its inertia.
Forces Involved
* Gravity: Both masses experience a downward force due to gravity (m1g and m2g).
* Tension: The string exerts an upward force on both masses (T).
Newton's Second Law
We'll use Newton's Second Law (F = ma) to find the acceleration:
1. Free Body Diagrams: Draw separate free body diagrams for each mass:
* Mass 1 (m1):
* Downward force: m1g
* Upward force: T
* Mass 2 (m2):
* Downward force: m2g
* Upward force: T
2. Equations of Motion: Apply Newton's Second Law to each mass:
* Mass 1: T - m1g = m1a
* Mass 2: m2g - T = m2a
3. Solve for Acceleration (a):
* Add the two equations together to eliminate T:
m2g - m1g = (m1 + m2)a
* Simplify and solve for a:
a = (m2 - m1)g / (m1 + m2)
Calculations
* m1 = 30 grams = 0.03 kg
* m2 = 40 grams = 0.04 kg
* g = 9.8 m/s² (acceleration due to gravity)
Substitute the values into the equation:
a = (0.04 kg - 0.03 kg) * 9.8 m/s² / (0.03 kg + 0.04 kg)
a ≈ 1.4 m/s²
Answer:
The acceleration of the system is approximately 1.4 m/s².