Question

the light from the laser beam travels at a speed of 300000000 m/s. How far will it travel in 5 nanoseconds? ​

Answer 1

$\orange{(Given) = The \: laser \: beam \: travels \: at \: }\\ \orange{a \: speed \: of \: 300000000 \: m/s.} \\ \\ \orange{(To \: find) = How \: far \: will \: laser \: beam\: }\\ \orange{travel \: in \: 5 \: nanoseconds. }\\ \\ ∴Let \: the \: distance \: travelled \: by \: laser\\ \: beam \: in \: 5 \: nanosecond \: be \: ‘x’, \\ \\(Hence, \: 1 \: second = {(10)}^{9} nanoseconds )\\ \\ ∴ \frac{ {10}^{9} }{3 \times {10}^{8} } = \frac{5}{x} \\ \\ ∴ \frac{10}{3} = \frac{5}{x} \\ \\ ∴10x =( 3 \times 5) \\ \\ ∴10x = 15 \\ \\ ∴x = \frac{15}{10} \\ \\ ∴ \green{ \boxed{x = 1.5}} \\ \\ \green{∴The \: laser \: beam \: will \: travel \: 1.5 \: m \: in \: 5} \\ \green{nano seconds.}$