Question

Given that $y=acos(\frac{t}{p}-qx)$, where $t$ represents time in second and $x$ represents distance in meter. Which of the following statements is true ?

• A. The unit of $x$ is same as that of $q$.
• B. The unit of $x$ is same as that of $p$.
• C. The unit of $t$ is same as that of $q$.
• D. The unit of $t$ is same as that of $p$.

Answer 1

Answer: (D)

The unit of $t$ is same as that of $p$.

$y=a\cos (\frac{t}{p}-qx)$
As $(\frac{t}{p}-qx)$ is a dimensionless quantity, $\frac{t}{p}$ has to be dimensionless.

Hence, dimensions of $t$ is same as that of $p$.

Unit of $t$ has to be same as that of $p$,