A wave sent out from a source is reflected back to the source in 1.0*10^-3 if the velocity of the wave is 3.0*17^8 the distance of the reflecting surface from the source is?

distance = speed * time

2 x in whatevers= 3*17^8 whatevers / time unit * 10^-3 sometime units

In other words ---- Without knowing units I can not help
remember the wave went twice the distance you want, there and back

The equation y=5sine (3x-4) where y is in millimetres and it's in second, present a wave motion. Determined the period

To find the distance of the reflecting surface from the source, we can use the formula for calculating the distance traveled by a wave. The formula is:

Distance = Velocity * Time

In this case, the velocity of the wave is given as 3.0 * 10^8 m/s, and the time it takes for the wave to travel from the source to the reflecting surface and back to the source is 1.0 * 10^-3 seconds.

Substituting the given values into the formula, we get:

Distance = (3.0 * 10^8 m/s) * (1.0 * 10^-3 s)

To multiply the numbers in scientific notation, we need to multiply the coefficients (3.0 and 1.0) together and add the exponents (8 and -3) together:

Distance = (3.0 * 1.0) * (10^8 * 10^-3) m

Since multiplying the coefficients gives us 3.0, and multiplying 10^8 by 10^-3 also gives us 10^5, we have:

Distance = 3.0 * 10^5 m

So, the distance of the reflecting surface from the source is 3.0 * 10^5 meters.