In desert the day are very hot and night are very cold ,why?​

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

Astudent is working in the lab to determine how time affect impulse the student keeps the force the same in each row but changes impact the time some data is shown witch trial has the greatest a student is working in the lab to determine how time affect impulse the student keeps the fours the same in each row but change is the impact time some data shown witch trial has the greatest impulse

At what time will the interfering waves have an amplitudeof zero?