Answer:
Step-by-step explanation:
degree 1
Answer:
The sidewalk moves at 0.5 ft/sec
Josie's speed walking on a non-moving ground is 3.5ft/sec
Step-by-step explanation:
Let x represent the speed of the side walk and y represent her walking speed
It takes Jason's 8-year-old daughter Josie 44 sec to travel 176 ft walking with the sidewalk
Distance = speed × time
176 = (x+y)×44
44x+44y = 176
x+y = 4 .......1
It takes her 7 sec to walk 21 ft against the moving sidewalk in the opposite direction).
21 = (y-x)7
7y - 7x = 21
y - x = 3 ......2
Add equation 1 to 2
2y = 7
y = 3.5 ft/sec
From equation 1
x + y = 4
x = 4 - 3.5 = 0.5
x = 0.5 ft/sec
The sidewalk moves at 0.5 ft/sec
Josie's speed walking on a non-moving ground is 3.5ft/sec
The answer is a I'm pretty sure
(a) Take the Laplace transform of both sides:
where the transform of 
comes from
![L[ty'(t)]=-(L[y'(t)])'=-(sY(s)-y(0))'=-Y(s)-sY'(s)](https://tex.z-dn.net/?f=L%5Bty%27%28t%29%5D%3D-%28L%5By%27%28t%29%5D%29%27%3D-%28sY%28s%29-y%280%29%29%27%3D-Y%28s%29-sY%27%28s%29)
This yields the linear ODE,
Divides both sides by 
:
Find the integrating factor:
Multiply both sides of the ODE by 
:
The left side condenses into the derivative of a product:
Integrate both sides and solve for 
:
(b) Taking the inverse transform of both sides gives
![y(t)=\dfrac{7t^2}2+C\,L^{-1}\left[\dfrac{e^{s^2}}{s^3}\right]](https://tex.z-dn.net/?f=y%28t%29%3D%5Cdfrac%7B7t%5E2%7D2%2BC%5C%2CL%5E%7B-1%7D%5Cleft%5B%5Cdfrac%7Be%5E%7Bs%5E2%7D%7D%7Bs%5E3%7D%5Cright%5D)
I don't know whether the remaining inverse transform can be resolved, but using the principle of superposition, we know that 
is one solution to the original ODE.
Substitute these into the ODE to see everything checks out:
