Acceleration A V T Acceleration Change in Velocity

Acceleration A = ΔV T Acceleration= Change in Velocity* time *Change in velocity = final velocity-starting velocity m/s/s = m/s s

Change in Velocity n n n Each time you take a step you are changing the velocity of your body. You are probably most familiar with the velocity changes of a moving bus or car. The rate at which velocity (speed or direction) changes occur is called acceleration.

Positive acceleration Negative acceleration

- A constant acceleration produces a straight line or linear slope (rise/run). - The slope of a nonlinear velocity-time graph (rise/run) will predict an objects instantaneous acceleration.

Problem 1: A car accelerates from a stop to 60 m/s in 6 seconds. What is the car’s acceleration? Equation Velocity(final) - Velocity(original) Acceleration = = time 60 m/s – 0 m/s 6 seconds 60 m/s 6 seconds 10 m/s/s

Problem 1: A car accelerates from a stop to 60 m/s in 6 seconds. What is the car’s acceleration? Data Table Time (sec) Distance (miles) Velocity (m/h) Accel (m/h/s) 0 0 1 5 10 10 2 20 20 10 3 45 30 10 4 80 40 10 5 125 50 10 6 180 60 10

Problem 1: A car accelerates from a stop to 60 m/s in 6 seconds. What is the car’s acceleration? Graph x-t 200 Distance (meters) 180 160 140 120 100 Distance (meters) 80 60 40 20 0 0 1 2 3 4 5 6 7

Problem 1: A car accelerates from a stop to 60 m/s in 6 seconds. What is the car’s acceleration? Graph v-t 70 Velocity (m/s) 60 50 40 Velocity (m/s) 30 20 10 0 0 1 2 3 4 5 6 7

Problem 1: A car accelerates from a stop to 60 m/s in 6 seconds. What is the car’s acceleration? Graph a-t 12 Accel (m/s/s) 10 8 6 Accel (m/s/s) 4 2 0 0 1 2 3 4 5 6 7

Problem 2: A car traveling at 60 mph slams on the breaks to avoid hitting a deer. The car comes to a safe stop 6 seconds after applying the breaks. What is the car’s acceleration? Acceleration = Velocity(final) - Velocity(original) time = 0 mph - 60 mph 6 seconds = - 10 miles per hour per second