Acceleration Introduction

Acceleration Introduction

Acceleration is Chang in Velocity over time

• increasing velocity

• decreasing velocity (acceleration is negative)

• changing direction

Multiple Select

Select all examples of acceleration (more than 1 is correct)

• a car speeding up

• a car slowing down

• a car turning

• a car staying the same speed

• a car stopped on the side of the road

Example:

• Roadrunner is at 0m/s before we start the stopwatch

• At 5 seconds, the new velocity is 10m/s

•  $acceleration\ =\ \frac{change\ in\ velocity}{change\ in\ time}$  

•  $acceleration\ =\ \frac{10\ \frac{m}{s}}{5s}$  =  $2\ \frac{m}{s^2}$  

Multiple Choice

What are the units for acceleration when you divide m/s by s?

•  $\frac{m}{s}$  
  

•  $\frac{m}{s^2}$  

• m

•  $\frac{m^2}{s}$  

Multiple Choice

If an object is traveling at 2m/s then 6 seconds later is is traveling at 14m/s, what was its acceleration during that time?

• $\frac{12\ \frac{m}{s}}{6s}\ =\ 2\ \frac{m}{s^2}$

• $\frac{14\ \frac{m}{s}}{6s}=2.33\ \frac{m}{s^2}$

• $\frac{2\ \frac{m}{s}}{14\ \frac{m}{s}}=0.14\ \frac{m}{s^2}$

For fractions, when you divide a fraction by a fraction, you flip the bottom and multiply

•  $\frac{\ \ \ \ \ \ \ \frac{m}{s}\ \ \ \ \ \ }{s}=\frac{\ \ \ \ \ \ \ \frac{m}{s}\ \ \ \ \ \ }{\frac{s}{1}}=\ \frac{m}{s}\times\frac{1}{s}=\frac{m}{s^2}$