Dynamics: Acceleration due to Gravity & Projectile Motion ☄️ - SAT Physics Learning & Test Prep
February 14, 2020·2 min
The episode begins by defining free fall, where an object's weight is the only force acting on it, leading to constant acceleration due to gravity. It specifies the average acceleration on Earth as 9.81 meters per second squared. Projectile motion is introduced as the motion of an object thrown into the air, subject only to gravity, with air resistance assumed negligible. A key principle is that horizontal and vertical components of projectile motion are independent, allowing separate equation solving. The displacement vector x is described as making an angle theta to the horizontal, with vertical component x sine theta and horizontal component x cos theta. Projectiles are noted to be acted upon only by gravity, so vertical acceleration equals 9.81 m/s², while horizontal acceleration is zero. Velocity components can also be separated. The episode outlines steps for solving projectile motion problems: first resolve horizontal and vertical components of displacement, velocity, and acceleration; then choose appropriate kinematic equations for each component, which may differ; next, solve each component separately using the identified equations; if needed, recombine components using Pythagoras' theorem to find total velocity, displacement, and angle. The host thanks listeners and encourages consolidating knowledge via a linked course.
