I don't think an object can exert a force on itself.
Try it: Get up on a skateboard, and see if you can do anything to yourself that makes you start moving ... without touching anything else.
It'll be easy to tell if you succeed. If you actually do exert an unbalanced force on yourself, then you'll begin to accelerate.
Answer:
they will move away from each other
Speed of sound in cold air < Speed of sound in Warm air < Speed of sound in hot molten lead < Speed of sound in water
Explanation:
Step 1:
Speed of sound in water varies from 1450 to 1498 meters per second
Speed of sound in Hot Molten lead is approximately 1210 meters per second
Speed of sound in warm air is approximately 338.89 meters per second
Speed of sound in cold air is approximately 293.33 meters per second
Step 2:
In warm air sound travels faster than that of sound travelling nature in cold air.
∴ Speed of sound in cold air < Speed of sound in Warm air < Speed of sound in hot molten lead < Speed of sound in water
Speed of sound in cold air the slowest while Speed of sound in water is the fastest mean.
time=distance/speed
1.6/100 secs = 0.016secs=16millisecs