Projectiles Motion in Two Dimensions Chapter 7 Projectile An object launched into the air by a force Trajectory The path followed by a projectile Horizontal Motion The red ball moves horizontally at equal intervals (constant velocity) It is not speeding up or slowing down Independence of Motion All the balls fall at the same rate The horizontal and vertical motions are independent of each other Projectile Motion Equations Objects Launched at an Angle Range (R) The horizontal distance traveled by a projectile Velocity Components Determine the vertical (y) and horizontal (x) components of the initial velocity. Projectiles at an Angle Then use the values in the original equations Hang-Time equation Should be negative 2 Maximum Height equation Same equation as before Time = the total time Why? Range equation Horizontal distance Same equation as before X = Vx t 7.2 Periodic Motion Repeating Motion An object on a string Pendulum Bouncing on a spring Circular Motion Velocity is perpendicular (tangent) to the radius Centripetal Acceleration Toward the center The rate of change of tangential velocity Period Period (T) is the time of a complete revolution 2 pie r = circumference = distance Velocity = distance / time Centripetal Acceleration Equation Centripetal Forces There must be a force to cause acceleration Centripetal Force Equation Newtons second law Changing Circular Motion: Torque Simple Harmonic Motion Amplitude Pendulum The period of the pendulum depends only the length. NOT mass or amplitude Pendulum Can be used to calculate g at a specific location