How do I find missing terms in kinematic equations?

In summary: and use the one that best fits the data :wink:you need to learn all of them and use the one that best fits the data :wink:
  • #1
cneedshelp
14
0
An Olympic sprinter can accelerate from rest out of the blocks to a top speed of about 11.5 m/s. This is accomplished in the first 15 m of a race. What is the average acceleration of the first sprinter?
Given- vi- 11.5 m/s
Distance-15m
Vf-?
t-?
Which formula do I use to find these missing terms?
 
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  • #3
Last edited by a moderator:
  • #4
s is always distance :wink:
 
  • #5
tiny-tim said:
s is always distance :wink:

Oh haha thank you. :)
Now how do you find the different times?
 
  • #6
what times?? :confused:

(i don't see any times in the question :redface:)
 
  • #7
tiny-tim said:
what times?? :confused:

(i don't see any times in the question :redface:)

You have to find acceleration, the formula is vf-vi over tf-ti right?
 
  • #8
that formula certainly works if you know t

but you only know vi vf and s, and there is a formula using that information :wink:
 
  • #9
tiny-tim said:
that formula certainly works if you know t

but you only know vi vf and s, and there is a formula using that information :wink:

d = vt + (1/2)at^2
is that the formula?
 
  • #10
cneedshelp said:
d = vt + (1/2)at^2
is that the formula?

no of course not :confused:
 
  • #11
tiny-tim said:
no of course not :confused:

Im not sure which formula to use...
 
  • #12
what's their _average_ speed during that 15m ?
so how long should it have taken them to go 15m, at that average speed?
 
  • #13
Last edited by a moderator:

1. What is average acceleration?

Average acceleration is the change in velocity over a period of time. It is a measurement of how quickly an object's speed is changing.

2. How is average acceleration calculated?

Average acceleration is calculated by dividing the change in velocity by the time it took for that change to occur. The formula for average acceleration is a = (vf - vi) / t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time.

3. What is the difference between average acceleration and instantaneous acceleration?

Average acceleration refers to the overall change in velocity over a period of time, while instantaneous acceleration is the acceleration at a specific moment in time. Average acceleration considers the entire motion of an object, while instantaneous acceleration only looks at a specific point in time.

4. What is the unit of measurement for average acceleration?

The unit of measurement for average acceleration is meters per second squared (m/s²) in the metric system. In the imperial system, it is measured in feet per second squared (ft/s²).

5. How is average acceleration used in real life?

Average acceleration is used in various fields such as physics, engineering, and sports. In physics, it is used to describe the motion of objects and their changing velocity. In engineering, it is used to design and test machines and structures. In sports, it is used to analyze and improve the performance of athletes.

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