Eg. 3. Analyze the following system (at rest) and solve for the unknown forces of tension, T1 and T2. Eg. 4. A locomotiv
Dynamics: Note 4
Applying Newton’s Third Law/Tension in Ropes N3L states that if object A applies a force to object B, then object B applies an equal but opposite force back on object A. We must use this fact when we have a system in static equilibrium or when a system is accelerating. We can compensate for either scenario (static or accelerating) using Newton’s Second Law in each direction (x and y). Tension in a rope can be thought of a force value needed to balance a system. When solving for tension in a question, a system of equations need to be setup. Eg. 1. The figure below shows three masses connected by strings and hung vertically. Determine the tension in the three strings. 15.0 kg 7.0 kg 13.0 kg Eg. 2. Analyze the following system (at rest) and solve for the unknown forces of tension, T1 and T2. T 40.0 T 52.0 kg 1
o
2
Dynamics: Note 4 Eg. 3. Analyze the following system (at rest) and solve for the unknown forces of tension, T1 and T2. T1 65
T2
o
50o
35.0 kg
Eg. 4. A locomotive can apply a force of 65 kN to pull a train. If the train has 4 cars (attached with cables) with the following masses: (assume no friction)
113 Tonnes
54 Tonnes
26 Tonnes
38 Tonnes
Determine the tension on each cable as the train begins to accelerate.
