Physics 11 Mr. Jean February 8 th, 2012

The plan: Video clip of the day Lab contracts Constant acceleration equations Constant accelerations

Example: x f - x i = v i t + ½ (a) (t 2 ) Over the distance of 4000m Jessica’s car accelerates at the rate of 30m/s 2 [E] with for 15 seconds. What is Jessica’s initial velocity?

Constant acceleration equation #3 v f 2 = v i 2 + 2a (x f - x i ) –v f = velocity (m/s) –v i = initial velocity (m/s) –a = acceleration (m/s 2 ) –x f = final distance (m) –x i = initial distance (m)

Constant acceleration: v f 2 = v i 2 + 2a (x f - x i ) Dominique stands on the top floor of a building and drops a penny. The penny hits the ground with final velocity is 81m/s. If the acceleration experience by the penny is 10m/s 2, how far did the penny drop? Important assumptions:

Gravity: An object is at rest and is dropped 1 meter. The acceleration of gravity is -9.81m/s 2. Gravity provides us with one of the most common types of constant acceleration. What is gravity?

Gravity: An object is at rest and is dropped 1 meter. The acceleration of gravity is -9.8m/s 2. How long does it take to hit the ground? HINT: x f - x i = v i t + ½ (a)(t 2 )

To do: Basic Kinematics Review Sheet Text book readings –Read pages –p. 41 – 45 –p. 47 – 49 –p. 51 – 52 –p. 61 – 64 –Friday we are in the lab.