2.3 Acceleration

Acceleration & Variables  Acceleration: the rate at which its speed changes  Acceleration means your speed will steadily increase  The amount of acceleration depends on the angle of the hill  Dependent variable: the variable in an experiment that changes based on choices made by you (y-axis)  Independent variable: the variable in an experiment that is changed by you; the dependent variable is affected by this (x-axis)

Acceleration Formula  Acceleration = change in speed change in time  Example  A car rolls down a ramp and you measure times and distances.  Car was going 50cm/sec when the timer said 0.10sec  Car was going 150cm/sec when the timer said 0.60sec  Calculate the acceleration in cm/sec/sec.

Acceleration or Deceleration  Acceleration occurs whenever the speed changes, whether the speed increases or decreases!  Deceleration: if you slow down, your acceleration is in a negative direction  Any time you change speed or direction, you are accelerating  Gravity: pulls everything down to the center of Earth  The acceleration of gravity would be different on other planets  Free fall: if you drop something straight down, it will accelerate

Scientist Spotlight Isaac Newton  Three laws of motion  Developed calculus  Drew knowledge from Aristotle and Strato (Greek scientists 365 B.C.)  Also drew knowledge from Simon Stevinus and Galileo (1580s)  All objects fall equally fast, if no other forces act on them