The student drops one cannonball, and exactly 1.0 ss later drops the other cannonball from the same height. What is the time interval between the first cannonball striking the ground and the second cannonball striking the ground?

If 1/5 of the students are in the football team and the class has 40 students, you need to multiple this numbers to know the exact number of students that form the team.40 x 1/5 = 8 studentsif 4 more students join: 8+4= 12 studentsto know the %: 40 students are equivalent to the whole class (100%). then 12 students are how much %? 40 students  = 100%12 students  =    x  %x= 30% of students are in the team.