A Radar Receiver Indicates That a Pulse Return as an Echo

question 57

Multiple Choice

A radar receiver indicates that a pulse return as an echo in $20 \mu \mathrm { s }$ after it was sent. How far away is the reflecting object? $\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$

• A) \(6.0 \mathrm {~km}\)
• B) \(9.0 \mathrm {~km}\)
• C) \(3.0 \mathrm {~km}\)
• D) \(1.5 \mathrm {~km}\)