Question

what is the speed of all electromagnetic waves travelling in a vacuum? 300,000,000 meters/second 300,000 kilometers/second 300 meters/second 3,000 kilometers/second

Explanation:

Step1: Convert units

We know that \(1\) kilometer \( = 1000\) meters.
So \(300000\) kilometers \(=300000\times1000 = 300000000\) meters.

Step2: Analyze options

• Option 1: \(300000000\) meters/second.
• Option 2: \(300000\) kilometers/second \(=300000\times1000\) meters/second \( = 300000000\) meters/second.
• Option 3: \(300\) meters/second is much smaller.
• Option 4: \(3000\) kilometers/second \(=3000\times1000=3000000\) meters/second.

In a vacuum, the speed of electromagnetic waves is \(c = 3\times10^{8}\) meters/second or \(300000\) kilometers/second.

Answer:

B. \(300,000\) kilometers/second