Video: Solving Word Problems Involving Direct Proportions

Video Transcript

The velocity 𝑣 of an object in metres per second is directly proportional to the time 𝑡 in seconds. This relationship can be expressed in the equation 𝑣 equals 9.8𝑡. Find the value of 𝑡 when 𝑣 equals 637 metres per second.

So here’s our equation. And we’re to find the value of 𝑡 when 𝑣 is 637 metres per second. So we can replace 𝑣 with 637. And now we can solve for 𝑡. So we need to divide both sides by 9.8. So 65 is equal to 𝑡. Therefore, when the velocity is equal to 637 metres per second, the time is 65 seconds.