What happens to wavelength as a wave leaves the air and enters the Perspex? a.
It decreases
c.
It stays the same
b.
It increases
d.
It becomes irregular

Please select the best answer from the choices provided

A: It decreases.

Explanation:

Hopefully this helps!

each year on this day, i make it a point to listen to dr. martin luther king jr.’s great “i have a dream” speech. it’s electrifying every single time.

the content of dr. king’s speech, his inspiring presence, and the moment in history all came together to make the iconic “i have a dream” speech the defining moment of the american civil rights movement. but there are several other reasons why this speech, delivered over 50 years ago, remains an example of one of the best speeches in american history.

since part of my job is to people become better presenters, i’ve noticed several techniques that we can all learn from and be inspired by in this magnificent speech.

it’s anchored in a powerful related location

in most cases, you can’t handpick the spot to give a presentation, as mlk did for supreme symbolic effect when he stood on the steps of the lincoln memorial and echoed the opening words of the gettysburg address (“five score years ago . . ). but you absolutely can amplify your message by adapting it to your setting and location.

in a place once known as north america, now known as panem, is a very rich city surrounded by twelve districts. every year because this very rich city, known as the capitol, is so rich and likes to think they control all the districts - which they do - there is something known as the hunger games! this is where two children, one boy and one girl from each district from the ages of twelve to eighteen, have to leave their families and compete in the hunger games, a live event that is aired on tv's all over panem. when katniss everdeen, aged sixteen from district 12, has to volunteer to take the place of her twelve-year-old sister prim after prim's name is called forth to become the 23rd member to compete in the 74th hunger games, she promises to prim that she will win! katniss doesn't believe she's coming out alive - but she's not going down without a fight.

because district 12 is so poor, katniss has been close to death many times from starvation but she's made it through it. but this is a different kind of close to death; this katniss doesn't know if she can survive.

she doesn't want to hurt, or kill anyone but when it comes down to it katniss' instinct is to survive. but when she starts to have confusing feelings about the boy from her district who is also her fellow contender, things get worse, and then she teams up with the girl from district 11 and only one person can survive. but who will it be? will her feelings get the better of her? will she let someone else win so they don't have to die? if katniss is going to win she's going to have to be brutal. she's going to have to kill!