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.
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.
What is the effect of one object exerting a force on another object?
The second object exerts an equal and opposite force back on the first object.
What happens if the masses in an Atwood machine are equal?
The system remains in equilibrium (no acceleration).
What happens when you push on a wall?
The wall pushes back on you with an equal and opposite force.
What is the effect of Dave pushing off the ground?
Dave accelerates upwards.
What happens when a swimmer pushes on the wall?
The wall pushes back on the swimmer, propelling them forward.