Answer to problem number 2 on the Grade 7 Numbers and Operations Quiz 1
To find the speed of an object, divide the distance
traveled by the time it takes to travel that distance. In this problem,
you are told that the ball rolls 90 feet in 1 minute, so one way to
write the speed is 90 feet/min. However, you are asked to find the
answer in feet per second. There are 60 seconds in one mintue, so the
speed (distance/time) can also be written as 90 feet/60 sec or 3/2 feet
per second which is the same as 1.5 feet per second.