Question Video: Changing the Subject of a Formula

Video Transcript

The final velocity of an object with uniform acceleration can be calculated using the formula 𝑣 equals 𝑢 plus 𝑎𝑡. Make 𝑡 the subject.

In order to make any variable the subject of a formula, we need to rearrange the formula so that that variable or letter is on its own. As we want to make 𝑡 the subject, we begin by subtracting 𝑢 from both sides of the equation. On the left-hand side, we’re left with 𝑣 minus 𝑢. And on the right-hand side, we’re left with 𝑎𝑡 as the 𝑢s cancel.

Our second step is to divide both sides of this new equation by 𝑎. The left-hand side of the equation becomes 𝑣 minus 𝑢 divided by 𝑎. On the right-hand side, 𝑎𝑡 divided by 𝑎 is 𝑡 as the 𝑎s cancel.

We can therefore say that rearranging the formula 𝑣 equals 𝑢 plus 𝑎𝑡 to make 𝑡 the subject gives us 𝑣 minus 𝑢 divided by 𝑎.