# Tutor profile: Sofia T.

## Questions

### Subject: Electrical Engineering

What is a Zener diode?

A Zener diode is a type of semiconductor device that allows the current to flow in opposite direction.

### Subject: Physics

You have three mediums and want to calculate the speed of sound through all of them, explain through which medium will sound pass faster and why? Mediums are Solid, Liquid and Gas.

Sound travels as longitudinal waves, they will travel the fastest from solids. The reason for this is that molecules in a solid are bonded closely. The order of speed of sound from all these mediums can be given as following: Solid > Liquids > Gas

### Subject: Algebra

Find out the value of x for the following equation. 15x+4 = 5x-32

Solution: Step 1: To solve this equation to find the value of x, we have to rearrange this equation so that values with x are at one side of the equation and constant values on the other. So by rearranging we get 15x-5x = -32-4 Note: when values are moved from left to right or right to left of an equation the signs associated with them also change. Step 2: Now we shall perform the calculations 10x = -36 Step 3: We only need x on the left-hand side so we shall move 10 on the right-hand side of the equation. As we can see that 10 is being multiplied by x so it will be in the division when it moves to the right-hand side. x= -32/10 x= -3.2 or -16/5

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