Passage: "Radar measures a vehicle's speed by sending out radio waves that bounce off the moving vehicle and return to the device. The change in the returning wave's frequency reveals how fast the vehicle is traveling. Lidar performs a similar task using pulses of laser light instead of radio waves." According to the passage, how does radar differ from lidar?

1. Radar uses radio waves while lidar uses laser light
2. Radar measures distance and lidar measures color
3. Radar works only at night
4. Lidar cannot measure speed