Radio waves travel at the speed of light . How long would it take the CIA to send a message to a spacecraft a distance of 7.5E6 m from earth? 2.5E-2 s 2.25E15 s 40 s 4.2E-2 S

## Step 1<br />The speed of light is approximately \(3 \times 10^8\) meters per second. This is the speed at which radio waves, as a type of electromagnetic radiation, travel.<br /><br />## Step 2<br />To find out how long it would take for a message to travel a certain distance, we can use the formula:<br />### **Time = Distance / Speed**<br /><br />## Step 3<br />In this case, the distance is \(7.5 \times 10^6\) meters and the speed is \(3 \times 10^8\) meters per second.<br /><br />## Step 4<br />Substitute the given values into the formula:<br />### **Time = \(7.5 \times 10^6\) m / \(3 \times 10^8\) m/s**<br /><br />## Step 5<br />Calculate the above expression to get the time in seconds.