Final answer:
A radiative electric field is first detected at location h approximately 73.3 nanoseconds after it is emitted, assuming it travels at the speed of light.
Step-by-step explanation:
To determine at what time a radiative electric field is first detected at location h at < 0,22, 0 > m, we need to know the speed at which electromagnetic waves propagate. In a vacuum, this speed is the speed of light, c, which is approximately 3 x 108 m/s. Given that no other specific information about the medium or additional factors affecting the propagation speed is mentioned, we'll assume that the wave travels at the speed of light.
The radiative electric field due to an electromagnetic wave is detected at the point when the wavefront reaches that location. If we denote the origin of the wave as point O (0, 0, 0), and location h as point H (0, 22, 0), the distance d between O and H is 22 meters.
Since the electromagnetic wave travels at speed c, the time t it takes to reach H is t = d / c = 22 m / 3 x 108 m/s.
We calculate the time t:
t = 22 m / (3 x 108 m/s) = 7.33 x 10-8 seconds.
Therefore, a radiative electric field is first detected at location h approximately 73.3 nanoseconds after it is emitted from the origin.