All Flashcards
What is the key difference between action-reaction forces and balanced forces?
Action-reaction forces act on different objects; balanced forces act on the same object.
Compare the magnitude and direction of action and reaction forces.
Equal in magnitude, opposite in direction.
Compare the effect of action-reaction forces versus balanced forces on an object's motion.
Action-reaction forces do not cancel each other out because they act on different objects. Balanced forces cancel each other out because they act on the same object, resulting in no net force and therefore no acceleration.
Compare the forces acting on two blocks connected by a string.
Force F applied to m1: Tension T and force F act on m1. Force F applied to m2: Tension T acts on m2.
Compare the assumptions made for the string and pulley in an Atwood machine.
String: Massless. Pulley: Frictionless.
What are the steps to derive the acceleration formula for an Atwood machine?
- Draw free body diagrams for each mass. 2. Apply Newton's Second Law (ΣF=ma) to each mass. 3. Combine the equations to eliminate tension and solve for acceleration (a).
How do you identify force pairs according to Newton's Third Law?
- Identify the interacting objects. 2. Determine the type of force (tension, friction, gravity, etc.). 3. Visualize the direction of the forces; they must be opposite.
What is the first step in analyzing an Atwood machine problem?
Draw free-body diagrams for each mass, showing tension (T) and weight (mg).
After drawing free body diagrams, what's the next step in solving Atwood machine problems?
Apply Newton's Second Law (ΣF = ma) to each mass.
What is the final step to calculate the acceleration of an Atwood machine?
Eliminate tension (T) from the two equations and solve for acceleration (a).
In a typical Atwood machine diagram, label the forces acting on each mass.
For m1: Tension (T) upwards, weight (m1g) downwards. For m2: Tension (T) upwards, weight (m2g) downwards.
Label a free-body diagram for a block being pushed horizontally.
Applied force (F) to the right, Normal Force (N) upwards, Weight (mg) downwards, and Friction (f) to the left (if applicable).
Label the forces acting on a swimmer pushing off a wall.
Force by swimmer on wall (action), Force by wall on swimmer (reaction).
Label the forces acting on a block being pulled by a string.
Tension (T) along the string, weight (mg) downwards, normal force (N) upwards.
Label the forces acting on a child on a swing at rest.
Tension (T_L) and (T_R) upwards, Weight (W) downwards.