Will the diameter and mass of a ball effect how fast it will drop and how high it will bounce?

For my experiment I would like to see if the diameter and mass of a ball effect speed and height.
Jackson L.
Grade 6


No video provided


I think that if it is a smaller drop the smaller ball will drop faster and bounce higher because the smallest ball is a tennis ball and it is made to bounce high.  When it is a bigger drop I think the bigger ball will drop faster and bounce higher because it will go fast just it will take more time to gain speed because of air resistance.


  • Basketball:  Diameter 24cm, circumference 75.5cm, weight 1.21 lbs.
  • Volleyball: Diameter 20cm, circumference 65.25cm, weight 0.61 lbs.
  • Dodgeball: Diameter 16.5cm, circumference 56cm, weight 0.4 lbs.
  • Wiffleball: Diameter 7cm, circumference 22.25cm, weight 0.1 lbs.
  • Tennis Ball:  Diameter 6cm, circumference 20cm, weight 0.2 lbs.
  • Asked in 1891 to invent an indoor winter activity by his boss at a YMCA in Springfield, Massachusetts, James Naismith is credited as the founder of basketball. Naismith, a physical education teacher, also wrote the original basketball rule book and founded the University of Kansas basketball program.
  • basketball was originally played with a soccer ball and peach baskets, with referees having to retrieve the ball each time a player made a basket. In 1900, the string baskets we know today were introduced to the game and, later, backboards were attached to prevent spectators from blocking a shot.

  • Players never could advance the ball. Instead, each player had to throw it from wherever he caught it. The first team credited with advancing the ball by dribbling it played at Yale in 1897, and the official allowance for the dribble, just one per possession at first, were adopted four years later.

  • Naismith invented an indoor winter activity and wanted a game flexible enough to include whoever wanted to play. For a while, the total number of players was a default 18, nine per side, the same number that showed up for the very first game.

  • Shouldering, holding, pushing, tripping or otherwise striking an opponent was never allowed. However, such offenses were never considered fouls until 1910, with the advent of a rule disqualifying a player for committing four of them. That total was raised to five in 1946, in the inaugural rules of the Basketball Association of America (the original name of the National Basketball Association), and to six the next year.

  • That is because one of the official duties of early refs was timekeeping. Then again, there wasn’t that much time to keep: the 24-second shot clock wasn’t instituted until 1954, to combat stalling tactics NBA teams had begun to employ.

  • Naismith proposed two 15-minute halves, with five minutes of rest in between.

  • College basketball remains one of the most popular sports, but spectators remember the Michigan State vs. Indiana college basketball game of 1979 during the NCAA tournament, which is one of the best-rated games in the sport's history. As a matchup between Magic Johnson and Larry Bird, who had never played each other prior to this tournament, this game marked the beginning of having basketball greats and NBA stars.



  • Manipulated (Indapendant) Variable-  The five different types of balls, Three different heights,  The air pressure in each ball.


  • Responding (Dependant) Variable-  How fast the ball will drop,  how high it will bounce. 


  • Constant (Controlled) Variable-  Same person dropping and messuring the ball,  using the same ball on every drop,  dropping from the same three spots.    



  • #1: Going from three different levels I will count down from 3,2,1 then say go.  As soon as I say that I will drop one of five balls to see which one goes the fastest.                                                                                                                                
  • #2: The three different levels are, standing on ground, on stage and on a Eagles chair rack.  These levels will all be inside the Trinity Christian School gym and there will be no wind, pressure or temperature to affect the speed.  On all of these different heights I will be standing up and dropping the ball with no purposeful force so it is a fair test.                      
  • #3:  The five balls are, a basketball, volleyball, dodgeball, wiffleball and tennis ball.  I will be dropping the balls in this order every time and not earasing any speed scores.  I will also be doing each test the same amount of times so it can be as fair as possible.


  • Drop from the floor 126cm-   I was surprised as the biggest ball (basketball) actually dropped the fastest and bounced the highest.  The speed of the drop was from the fastest to the slowest and the fastest to slowest was in order from the biggest ball to the smallest.  And for the bounce the basketball still bounced highest then came the tennis ball it was like they were alternating from biggest to smallest then second biggest… and so on.


  • Drop from the stage 226cm-  Again on this drop the basketball was fastest and then came the wiffle ball surprisingly as it is fifty percent holes.  Third came the tennis ball followed by the dodgeball and the slowest out of all of them was the volleyball even though it is the second biggest.  For the bounce the basketball bounced highest by a large portion then followed by the volleyball.  The tennis ball came in third as the wiffleball was next slightly beating the dodgeball.


  • Drop from top of Eagles chair stack-  On the highest drop the smallest ball actually came in first for speed closely followed by the volleyball. Next came the wiffleball and for the first time the basketball was in forth.  That leaves only the dodgeball in last place.  When it was the bounce it was surprising that even though the basketball was pretty slow it still bounced the highest.  The tennis ball came in second as it was made to be bouncy next came the volleyball then dodgeball.  Finally the wiffleball bounced the lowest as it stayed around the same for most of all three heights.    


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After I completed the experiment I was very surprised to seee that my hypothesis was the exact opposite of what actually happened.  I thought that the smaller the drop the smaller ball would drop the fastest and that the bigger drop would have the bigger ball the fastest.  As you can see in my analysis the bigger balls drop faster on smaller drops yet the small balls dropped faster on the biggest drop.  For the actual question the diameter didn't effect it that much but the mass definitely was the key player.  


I could use this science experiment to know basic facts and know more random facts.  This seems pretty useless but it might actually win you some cash.  Even if it is not a lot it still is some.  One way to win some is through bets, most bets are random and weird.  You could create one and probably win some money.   Another way is through trivia games; sort of like the first way it could be weird and random questions.  Not just answering this question but it is also fun to know random, cool or weird facts.  The last way you could use this in a daily basis is that say you are playing street basketball, volleyball, dodgeball, pickle ball or tennis you could use this to your advantage.  In all of these sports it hits the ground at some time, you could use knowledge to know how hard or how fast you need to throw/hit it you could make it at an akward angle so it bounces weird and tey have a hard time recieving the pass or spike.

Sources Of Error

In this experiment there a lots of mistakes because it is impossible to make it perfect.  Every drop is going to be slightly off if I don't drop the ball at the exact second or when the timer stops that it is the exact time it hits the ground.  When the ball bounces it is hard to messure with a meter stick and it could easily be off by even centimeters and the whole test scores would be off.  Every drop I tried to not put any power in the drop and that all I did was let go of the ball.  Not only when the ball hits the ground, the timer could be off when we actually drop the balll.  









For my acknoledgements I would like to thank my mom, sister, brother, and dad for helping me do the actual experiment or just giving me support.  I don't know how I could do this experiment without them and even if I did manage to do it, it would not be accurate.