Answer:
Hear echo sooner on a hot day than on a cooler day.
Step-by-step explanation:
Temperature is one of the factors that determine the speed of sound. Speed of sound, which in this case is echo is calculated considering distance and time. Speed of sound is directly proportional to the temperature , therefore, when the temperature is hot, the speed of sound is faster than when the temperature is cold and vice versa. In conclusion, you would expect to hear the echo “hello” sooner on a hot day compared to a cold day provided all the other factors are kept constant.