#  When you are in motion, you are constantly adjusting your velocity and direction to match what is happening around you.  Changing velocity is called.

## Presentation on theme: " When you are in motion, you are constantly adjusting your velocity and direction to match what is happening around you.  Changing velocity is called."— Presentation transcript:

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2  When you are in motion, you are constantly adjusting your velocity and direction to match what is happening around you.  Changing velocity is called acceleration  For example, when a bus starts from a rest, its velocity increases. The bus accelerates.

3  Acceleration describes all situations in which velocity is increasing and decreasing  If acceleration does not change throughout it is called constant or uniform acceleration  The units for acceleration are the untis of velocity divided by the units for time

4  For example if a bus accelerates at +5m/s every second this is written as:

5  Other units can also be used, as long as they are a velocity to time comparison. For example, car advertisements sometime claim “0-100 in 5 seconds.”  What this means is that the car can accelerate from 0km/h to 100km/h in 5 s an acceleration of:

6  On average, at the end of each second the car is moving 20km faster than at the end of the previous second.

7  Astronauts are launched in a horizontal position because in that position the human body can briefly tolerate accelerations as great as 120m/s 2. In the vertical position, acceleration of only 30m/s 2 usually results in unconsciousness

8  Myriam Bedard accelerates on her skis from 6m/s [forward] to 15m/s [forward], a change of 9m/s[forward] in 1.5s. What is her acceleration during this time?

9  A skateboarder rolls down a hill with an average acceleration of +0.40m/s 2. He is on the hiss for 4.8s. What is his change in velocity?

10  Acceleration while slowing down would be shown using negative signs as it is negative acceleration or deceleration. The calculation process is the same only with negative signs

11  In a race, a car travelling at 53m/s pr 190km/h comes in for a pit stop and comes to a full stop in 5.0s. What is the deceleration?

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