what does the below rebus means?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

I am white when I am dirty, and black when I am clean. What am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

How is the moon similar to a dollar?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

John is asked to stand behind Jacob and Jacob is asked to stand behind John. Both of them feel confused about it and don't know what to do?

But it is quite possible, do you know how?

How can you leave a room with two legs and return with six legs?

We have arranged an array of numbers below. What you have to do is use any kind of mathematical symbol you know excluding any symbol that contains a number like cube root. You can use any amount of symbols but you have to come up with a valid equation for all of them.

0 0 0 = 6
1 1 1 = 6
2 + 2 + 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

Using Only Five 5's and any mathematical operator make sum as 37