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please help me work through this, in the second image I got some help but I don't understand where theya re getting some numbers like 108 and 109, thank you!

please help me work through this, in the second image I got some help but I don't-example-1
please help me work through this, in the second image I got some help but I don't-example-1
please help me work through this, in the second image I got some help but I don't-example-2
User Kustomrtr
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2.7k points

1 Answer

13 votes
13 votes

Answer:

0.01s : Average velocity = - 102.22 ft/s

0.005s : Average velocity = - 102.11 ft/s

0.002s : Average velocity = - 102.044 ft/s

0.001s: Average velocity = - 102.022 ft/s

Instantaneous velocity at t = 3 is - 102 ft/s

Step-by-step explanation:

The position-time function is expressed as

y = 30t - 22t^2

y(t) = 30t - 22t^2

1) To find the average velocity between t = 3 and t = 3 + 0.01 = 3.01, we would substitute these values into the position-time function. Thus,

y(3) = 30(3) - 22(3)^2 = - 108

y(3.01) = 30(3.01) - 22(3.01)^2 = - 109.0222

Average velocity = (- 109.0222 - - 108)/(3 - 3.01) = (- 109.0222 + 108)/0.01

Average velocity = - 102.22 ft/s

2) To find the average velocity between t = 3 and t = 3 + 0.005 = 3.005, we would substitute these values into the position-time function. Thus,

y(3) = 30(3) - 22(3)^2 = - 108

y(3.005) = 30(3.005) - 22(3.005)^2 = - 108.51055

Average velocity = (- 108.51055 - - 108)/(3 - 3.005) = (- 108.51055 + 108)/0.005

Average velocity = - 102.11 ft/s

3) To find the average velocity between t = 3 and t = 3 + 0.002 = 3.002, we would substitute these values into the position-time function. Thus,

y(3) = 30(3) - 22(3)^2 = - 108

y(3.002) = 30(3.002) - 22(3.002)^2 = - 108.204088

Average velocity = (- 108.204088 - - 108)/(3 - 3.005) = (- 108.204088 + 108)/0.002

Average velocity = - 102.044 ft/s

4) To find the average velocity between t = 3 and t = 3 + 0.001 = 3.001, we would substitute these values into the position-time function. Thus,

y(3) = 30(3) - 22(3)^2 = - 108

y(3.001) = 30(3.001) - 22(3.001)^2 = - 108.102022

Average velocity = (- 108.102022 - - 108)/(3 - 3.001) = (- 108.102022 + 108)/0.001

Average velocity = - 102.022 ft/s

To find the velocity function, we would differentiate the position time function. Thus,

v(t) = dy(t)/dt = 30 - 44t

To find the instantaneous velocity at t = 3, we would substitute t = 3 into v(t) = 30 - 44t

Thus,

v(3) = 30 - 44 x 3 = 30 - 132

v(3) = - 102

Instantaneous velocity at t = 3 is - 102 ft/s

User Wilder Valera
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2.8k points