How to find the average velocity?

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Can't someone please explain to me how to do question 2c and 9e? Thanks!

1 Answer
Sep 25, 2017

The average velocity is the average rate of change which is also the slope of the secant line: x2x1t2t1

Explanation:

Number 2
The first 3 seconds are from t=0 to t=3

At t=0, position is 11

and at t=3, position is (3)312(3)+11=16

So the average velocity is

(16)(11)30=273=9 cm/s

Number 9

x=t27t+12

Velocity: v=2t7

The particle moves in the negative direction from t=0 to t=3.5

It starts at x=12 and changes direction when it get to x=0.25 (at t=3.5
That distance is 12.25 cm

It then travels in the positive direction until it gets to 2at t=5).
That distance is 2.25.

The total distance traveled is 12.25+2.25=14.5 cm

The average speed is 14.55=2.9 cm/s.