Physics Fall Final

What is Newton’s First Law?

An object will remain at rest or in uniform motion unless acted upon by an external net force.

What happens to motion when forces are balanced?

A stationary object remains at rest, and/or a moving object continues at a constant velocity. This is known as equilibrium.

What causes unbalanced forces and what do they result in?

Occur when the sum of forces (Fnet) is not zero. They result in acceleration, which changes the object's velocity.

What is friction?

The force that opposes motion between two surfaces.

What is static friction?

A type of friction that prevents an object from starting to move when a force is applied. It acts between stationary surfaces.

What is kinetic friction?

A type of friction that occurs when two surfaces are sliding past each other. It is generally less than static friction.

What factors influence friction?

Surface roughness (coefficient of friction μ) and normal force (force pressing surfaces together).

What is Newton’s Second Law?

Acceleration is proportional to the net force and inversely proportional to mass.

How does doubling force or mass affect acceleration?

Doubling force → doubles acceleration, doubling mass → halves acceleration.

What is a free body diagram (FBD)?

Visual representation of all forces acting on an object, including direction and magnitude of forces (arrows), and force labels (e.g., gravity, normal, friction, applied).

How do you know if forces are balanced or unbalanced?

Balanced forces → object at rest or constant velocity, unbalanced forces → acceleration occurs

What does inertia refer to in Newton’s First Law?

The tendency of an object to resist changes in its motion. An object at rest stays at rest, and an object in motion stays in motion unless acted on by an external force.

What is the normal force and where does it act?

The support force exerted by a surface on an object. It acts perpendicular to the surface.

What is the relationship between friction and normal force?

Proportional to the normal force. If the normal force increases, friction force increases as well.

What force keeps an object at rest despite an applied push?

Static friction keeps the object stationary until the applied force overcomes it.

What does the slope of a position vs. time (x-t) graph represent?

Velocity. Steeper slope → faster velocity, flat slope → no motion.

What does the slope of a velocity vs. time (v-t) graph represent?

Acceleration. Flat line → constant velocity (no acceleration), positive slope → speeding up, negative slope → slowing down.

What does the area under a velocity vs. time (v-t) graph represent?

Displacement (change in position). Positive area → forward motion, negative area → backward motion.

How do you find velocity change from an acceleration vs. time (a-t) graph?

The area under the curve gives the change in velocity.

What does a curved position vs. time graph indicate?

Acceleration because the velocity (slope) is changing.

How do you analyze displacement from a velocity vs. time graph?

Calculate the area under the curve. Above the time axis → positive displacement, below the time axis → negative displacement.

What does it mean if a velocity vs. time graph has a flat line at zero?

The object is at rest (velocity = 0).

How do you relate acceleration to velocity and position?

Acceleration → change in velocity. Velocity → change in position.

What is centripetal force?

The inward force that keeps an object moving in a circle.

What is centripetal acceleration?

Acceleration directed toward the center of a circle.

What provides the centripetal force for satellites in orbit?

Gravity provides the centripetal force that keeps satellites in orbit.

What is Newton’s Law of Universal Gravitation?

All objects with mass attract each other with gravitational force.

How does gravitational force change when distance or mass changes?

If distance doubles → force decreases to 1/4, if mass doubles → force doubles.

What is Newton’s Third Law?

For every action force, there is an equal and opposite reaction force.

What is the Impulse-Momentum Theorem?

The change in momentum of an object is equal to the impulse applied to it.

What happens to force if the time of impact increases?

If the time of impact increases, the force decreases.

What is conservation of momentum?

In a closed system, total momentum before and after a collision is conserved.

What is the difference between elastic and inelastic collisions?

Elastic is when kinetic energy and momentum are conserved, and inelastic is when only momentum is conserved; objects may stick together.

How does Kepler’s Law relate to satellite motion?

Describe the motion of planets and satellites in elliptical orbits due to gravity.

What happens to centripetal force if velocity doubles?

Centripetal force increases by a factor of 4 because it depends on v²

Why is momentum conserved in collisions?

Because no external forces act on the system.