All Flashcards
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.
Define Newton's Third Law.
For every action, there is an equal and opposite reaction.
What is an action-reaction pair?
A pair of equal and opposite forces acting between two interacting objects.
Define 'action' in the context of Newton's Third Law.
The force exerted by one object on another.
Define 'reaction' in the context of Newton's Third Law.
The equal and opposite force exerted by the second object back on the first.
What is an Atwood Machine?
Two masses connected by a string over a pulley, used to demonstrate the relationship between force, mass, and acceleration.
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.