Kinematics and Dynamics Flashcards
(25 cards)
What is the difference between displacement and distance?
Displacement is a vector quantity representing the change in position (including direction), while distance is a scalar quantity representing the total path length traveled.
Define velocity and acceleration.
Velocity is the rate of change of displacement (vector). Acceleration is the rate of change of velocity (vector).
List the four SUVAT equations for uniformly accelerated motion.
- v = u + at
- s = ut + 1/2 at²
- v² = u² + 2as
- s = (u + v)/2 t
How are horizontal and vertical motions of a projectile related?
They are independent. Horizontal motion has constant velocity (no acceleration), while vertical motion has constant acceleration due to gravity (g).
State Newton’s First Law.
An object remains at rest or in uniform motion unless acted upon by a resultant external force.
State Newton’s Second Law.
F = ma, where F is the resultant force, m is mass, and a is acceleration.
State Newton’s Third Law.
For every action force, there is an equal and opposite reaction force (forces occur in pairs).
What is a free-body diagram?
A diagram showing all forces acting on an object, represented as vectors originating from the object’s center of mass.
What is the difference between static and dynamic friction?
Static friction prevents motion (Ff ≤ μs FN), while dynamic friction opposes motion (Ff = μd FN).
State Hooke’s Law.
F = -kx, where F is the restoring force, k is the spring constant, and x is the displacement from equilibrium.
Define linear momentum.
p = mv, where p is momentum (vector), m is mass, and v is velocity.
What is impulse, and how is it related to momentum?
Impulse (J = FΔt) equals the change in momentum (Δp).
State the law of conservation of momentum.
In a closed system, total momentum before a collision equals total momentum after the collision.
Write the formula for kinetic energy.
Ek = 1/2 mv².
Write the formula for gravitational potential energy near Earth’s surface.
Ep = mgh.
Write the formula for elastic potential energy in a spring.
Ep = 1/2 kx².
Define work done by a force.
W = Fscos(θ), where θ is the angle between the force and displacement.
Define power and give its formula.
Power is the rate of doing work: P = W/t = Fv.
Define efficiency.
η = Eoutput/Einput × 100%.
What is the drag force equation for a small sphere in laminar flow?
Fd = 6πηrv, where η is viscosity, r is radius, and v is velocity.
State Archimedes’ Principle.
The buoyant force equals the weight of the displaced fluid: Fb = ρVg.
What happens when an object reaches terminal velocity?
The drag force equals the object’s weight, resulting in zero net force and constant velocity.
When is mechanical energy conserved?
In the absence of non-conservative forces (e.g., friction, air resistance).
Distinguish between elastic and inelastic collisions.
Elastic: Kinetic energy is conserved. Inelastic: Kinetic energy is not conserved (but momentum is).
