The Kinematics Equations (1D Equations of Motion) Unit 2 Class Notes The Kinematics Equations (1D Equations of Motion) Accelerated Physics

Throw-Ups, Come-Downs, Throw-Downs Day #4 Throw-Ups, Come-Downs, Throw-Downs

To solve for “t”, use the quadratic formula  1 2 UP +, DOWN - a = -9.8 m/s2 v2 = 0 (at the top) v1 = 20 m/s a = -9.8 m/s2 v2 = 0 m/s To solve for “t”, use the quadratic formula 

2 1 3 UP +, DOWN - a = -9.8 m/s2 Dt12 = Dt23 v2 = 0 (at the top) v3 = -v1 Two VERY important things to know about the case where you throw an object up and catch it at the same height.

#2 2 v2 = 0 m/s v2 = 0 m/s 3 a = -9.8 m/s2 a = -9.8 m/s2 1 Dx = 30 m Due to the fact that the ball is thrown and caught at the same height …

#2 1 2 4 3 v1 = 24.25 m/s a = -9.8 m/s2 Dx = -1 m To solve for “t”, use the quadratic formula  Only positive times make physical sense

#3 A man launches a popcorn ball straight up into the air. It reaches its peak, and then begins to fall back to the ground. 4 seconds after it was released from the man’s hand, a bird catches the ball 20 ft above the ground. What was the velocity at which the ball left the man’s hand? Dt = 4 sec a = -32.2 ft/s2 Dx = 20 ft