<span>There's nothing on that list that may be damaged by increase in solar activity.
</span>
Answer:
a) 600 meters
b) between 0 and 10 seconds, and between 30 and 40 seconds.
c) the average of the magnitude of the velocity function is 15 m/s
Explanation:
a) In order to find the magnitude of the car's displacement in 40 seconds,we need to find the area under the curve (integral of the depicted velocity function) between 0 and 40 seconds. Since the area is that of a trapezoid, we can calculate it directly from geometry:
![Area \,\,Trapezoid=(\left[B+b]\,(H/2)\\displacement= \left[(40-0)+(30-10)\right] \,(20/2)=600\,\,m](https://tex.z-dn.net/?f=Area%20%5C%2C%5C%2CTrapezoid%3D%28%5Cleft%5BB%2Bb%5D%5C%2C%28H%2F2%29%5C%5Cdisplacement%3D%20%5Cleft%5B%2840-0%29%2B%2830-10%29%5Cright%5D%20%5C%2C%2820%2F2%29%3D600%5C%2C%5C%2Cm)
b) The car is accelerating when the velocity is changing, so we see that the velocity is changing (increasing) between 0 and 10 seconds, and we also see the velocity decreasing between 30 and 40 seconds.
Notice that between 10 and 30 seconds the velocity is constant (doesn't change) of magnitude 20 m/s, so in this section of the trip there is NO acceleration.
c) To calculate the average of a function that is changing over time, we do it through calculus, using the formula for average of a function:

Notice that the limits of integration for our case are 0 and 40 seconds, and that we have already calculated the area under the velocity function (the integral) in step a), so the average velocity becomes:

The first answer should be correct if not then the second one
The steel would expand by 4. 8 * 10^-3 cm
<h3>How to determine the linear expansion</h3>
The change in length ΔL is proportional to length L. It is dependent on the temperature, substance, and length.
Using the formula:
ΔL= α LΔT
where ΔL is the change in length L = 10cm
ΔT is the change in temperature = 60° - 20° = 40° C
α is the coefficient of linear expansion = 1.2 x 10^-5 °C
Substitute into the formula
ΔL = 
ΔL =
cm
Therefore, the steel would expand by 4. 8 * 10^-3 cm
Learn more about linear expansion here:
brainly.com/question/14325928
#SPJ1