# Hi, I need some help with a homework problem invovling acceleration

#### mindgame

1. Homework Statement
What is the acceleration of your car?

Time Velocity[ms]
1 8.8
2 12.82
3 16.25
4 20.46
5 24.22
6 28.09
7 31.77
8 35.24
9 39.32
10 42.37
11 44.61
12 46.63
13 49.01
14 50.53
15 52.1
16 52.32
17 53.6
18 53.44
19 53.74
20 53.25

http://img87.imageshack.us/img87/8674/velocitygraphob6.jpg [Broken]

2. Homework Equations

3. The Attempt at a Solution

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#### mindgame

I really just don't know where to start, is there an equation I need to use or is this much more complicated?

#### Kurdt

Staff Emeritus
Science Advisor
Gold Member
The definition of acceleration is the rate of change of velocity with time. What you need to do is find out how much the speed changed and in what time, then:

$$a= \frac{\Delta v}{t}$$

#### mindgame

(53.25 - 8.8) = 44.45

a = (44.45) / 20s

a = 2.2225 m/s

Is this right?

#### radou

Homework Helper
What's with the function in the upper right edge v(t) = 3.6688 t + 5.6189 ?

#### mindgame

That's just the slope of the trendline for the increasing part of the graph. He told us in class we had to show it.

#### cristo

Staff Emeritus
Science Advisor
Ok, so from above $$a= \frac{\Delta v}{t}$$ , or to put it another way, a is the gradient of the graph of v against t. Given your trendline, in the form y=mx+c, how can you read off the gradient?

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