Projectiles Optimal Angle Launch at Landing Level

Project #2622 on iSENSEProject.org

How does the angle of launch affect the horizontal distance an object will travel over a horizontal space?  To examine this, you will need:

1 marble launcher with adjustable angle muzzle and protractor

1 ball bearing

Masking tape

1 table

1 level adjustable-height chair

1 piece of thin plywood about 1 foot by 2 feet. 

1 meter stick

goggles for each member of each lab group

Directions:  

SAFETY:  Goggles MUST be worn at all times.  Anyone not wearing goggles will receive no credit for the lab.  NEVER point the launcher, loaded or un-loaded, towards anyone, towards a window, or towards yourself.  Keep your mouths shut--a flying or bouncing ball bearing against a tooth equals a broken tooth and lots of fun at the dentist's office.  Do not pull the spring beyond the second notch unless you are told to do so.  Anyone pulling past the second notch will receive no credit for the lab.  

Procedure:  

Assemble the launcher.  Place the piece of plywood on top of a lab chair and adjust the height of the lab chair so that the muzzle of the marble launcher is at the same height of the table.  

Set the launcher to 80 degrees above horizontal.

Place a ball bearing in the muzzle.

Cock the launcher to the second notch--the one that gives the second-least tension on the spring.  

Wearing goggles at all times, fire the ball bearing to the table and place a piece of masking tape where the ball-bearing lands.  Repeat 9 times for 80 degrees.  Measure the horizontal distance from the muzzle of the launcher to the pieces of masking tape and record. 

DIVISION OF LABOR:  One group member runs the gun.  Another member watches where the ball bearings land and marks with masking tape.  A third member captures the ball bearings after they have landed--or 'fields' the bounding balls.  When all shots for a given angle have been fired, the gunman measures with the meter stick; the 'fielder' records the data on the data sheet, and the tape person removes each piece of tape once the measure has been made and recorded.  

Repeat procedure for 70, 60, 50, 40, 30, 20, and 10 degrees.  

Record all values and take the average of the 10 shots for each angle.  

When done, enter your data manually to iSENSE when instructed.  

Visualize with angle on the horizontal axis and see if you can determine a pattern.  Be prepared to discuss the results when you can see how other groups did for data.

Questions:

1 As you go from 80 degrees to 10 degrees, what happens to how far the balls go?

 2 What seems to be the angle(s) that produce(s) the greatest distance?

 3 Can you account for the angle(s) being the most optimal?

Were there any difficulties with obtaining or making sense of the data?  Consider the consistency of how hard the gun fired, seeing where the ball bearings landed, and making the measurements with the meter sticks.

Do you have a hypothesis to suggest?  If you had the time, how would you test the hypothesis and why?