Answer:
I don't even know can anybody help this person
Vf =Vi + at
Vi =Vf - at
= 34 - 15•13
= - 161 m/s :/
Advantages of copper cables are that copper is an extremely powerful conductor of electricity and much more stable over time. It can withstand higher temperatures than aluminum and is more resistant to damage.
Disadvantages: Copper is more expensive and heavier and thus requires structural support.
Advantages of aluminum cables are that it is less expensive, easier to work with and light weight and so does not need structural support when strung over long distance.
Disadvantages: Aluminum is more susceptible to corrosion and requires periodic replacement. It needs much greater maintenance.
Advantages of steel cables are that steel does not rust, is fairly cheap and readily available. It has a higher tensile strength too.
Disadvantages: Steel cables are less ductile and are therefore more susceptible to fatigue.
Answer:
.
Explanation:
The average speed of an object is equal to total distance over total time.
- Distance traveled:
.
How much time is taken? This trip is divided into two halves, each of distance
.
Time spent on the first half of the trip:
.
Similarly, time spent on the second half of the trip:
.
In total:
.
Average speed:
.
This value turned out to be slightly different from the average of the speed during the two halves of the journey. The reason is that the object traveled at each speed for a different amount of time. It spent more time at the slower speed, which gives that speed a greater weight in the average. That explains why the average speed is closer to
rather than
.