calculusdunce
New member
- Joined
- Jun 11, 2021
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- 6
If you tell us what you did, then maybe we can tell you what you did wrong. Helpers here do not mind helping you but they need to know where you need help.Wait--the thing graded it wrong...what did I do wrong?
Professor Halls! If the base goes from 4 to 6 that is not a distance of 3! From 4 to 7 is a distance of 3.Since these are all straight lines, I wouldn't bother with integration- that's just the area under the line. Assuming each horizontal step is one second and each vertical step is one m/s^2, the area under the line from t= 0 to 4 is the area of the trapezoid with "bases" of 4 m/s^2 and 7 m/s^2 and "height" 4 s. The increase in velocity is ((7+ 4)/2)(4)= 11*2= 22 m/s. If the initial velocity was "v" then the speed after 4 seconds is v+ 22 m/s. From 4 seconds to 6 seconds, we have a horizontal line at a= 7. The area of a rectangle with height 7 and length 3 is 3(7)= 21. The speed after 6 seconds is v+ 22+ 21= 10. v= 10- 22- 21= -33 m/s.
I think that this is a perfect answer.[math]\displaystyle v(6) - v(0) = \int_0^6 a(t) \, dt[/math]
[math]10 - v(0) = 36[/math]
How are you calculating area when the unit magnitude of axes are unknown?[math]\displaystyle v(6) - v(0) = \int_0^6 a(t) \, dt[/math]
[math]10 - v(0) = 36[/math]
How are you calculating area when the unit magnitude of axes are unknown?
I was more concerned with the "magnitude" (scale) - opposed to units.Well, I guess I assumed that the units on the horizontal axis were seconds & meters per second squared on the vertical.
suffice it to say [MATH]v(6) - v(0) = \int_0^6 a(t) \, dt[/MATH] is correct w/o any assumptions.
I was more concerned with the "magnitude" (scale) - opposed to units.
i.e. 1 unit on x-axis =1 sec or 5 secs.
Dang! One of these days I am going to have to learn arithmetic!Professor Halls! If the base goes from 4 to 6 that is not a distance of 3! From 4 to 7 is a distance of 3.
A mathematician that knows arithmetic. How rare will that be!Dang! One of these days I am going to have to learn arithmetic!