Answer:

Explanation:
Given:
- mass of skier,

- initial velocity of skier,

- height of the hill,

- spring constant,

<u>final velocity of skier before coming in contact of spring:</u>
Using eq. of motion:



<u>Now the time taken by the skier to reach down:</u>



<u>Now we calculate force using Newton's second law:</u>




<u>∴Compression in spring before the skier momentarily comes to rest:</u>




The best answer is b - span.
A span is the distance between two bridge supports The supports may be towers, columns, or even the wall of a canyon.
There are many kinds of bridges but they all fall into three types namely beam, arch and suspension. The major difference between these three kinds of bridges is the distance that each can cross in a single span.
For example, a modern beam bridge is likely to span a distance of 200 feet, a modern arch can span 800 or 1000feet, and a modern suspension bridge can span up to 7000ft.
Answer:
Double blind experiment
Explanation:
It is an experimental method , which helps to avoid any impartiality and any error due to biasing .
The experiment give rise to very accurate results , which is very important for any experiment .
Hence , the new director Margaret , need to design a set of double - blind experiments.
This is called Joule's Law. It describes how things heat up due to electric current passing through them