How long is a straightened slinky

Copymaster 5 contains student instructions for this activity. Students need to decide on the shape of the paper they will use.

A square is the simplest but they may come up with other options, encourage them as they explore alternatives. If using a square of paper, the circumference of the ball can be used as either the length of the sides of the square, or the diagonal measurement. Using the diagonal measurement will result in less wrapping paper being used.

Measurements will also need to allow for some overlap of paper. Discuss with the students what an appropriate overlap might be. When students have finished the task have them cut out a piece of paper to the measurements they have worked out and try to wrap the ball.

Is it possible? Would they change their answer now they have tried it? If so, what false assumptions were made in the measuring process? Students could make comparisons using the formulae for the surface area of a sphere. This week your child has some measuring work to do with circles. Ask them to explain the steps they have gone through to solve this measuring task.

Log in or register to create plans from your planning space that include this resource. Use the resource finder. Home Resource Finder. GM Interpret and use scales, timetables, and charts. AO elaboration and other teaching resources. Specific Learning Outcomes. Describe a method to measure the length of circular objects. Measure length using metres, centimeters and millimeters. Calculate the circumference of a circle from a measurement of diameter. Description of Mathematics.

Ideally all balls the same size. Large sheets of paper, A1 size is ideal Copymaster 5 Copymaster 6 contains a general template that can be used to help students structure their work. Required Resource Materials. Station One In this station students work together to devise a way to measure the length of slinky: a coiled plastic toy. Station Two Students draw a diagram of the label on a can, taking measurements from the can to ensure their diagram is accurate.

Possible methods include: Using a piece of string or paper strip to measure around the can and directly transferring this length to the diagram. Using a piece of string or paper strip to measure around the can, measuring the piece of string in cm and mm and using a ruler to draw the appropriate length line on the diagram.

The height of the label can be measured directly using a ruler. Station Three In this station students estimate, then measure, how many slices of tomato will fit around the edge of a pizza.

Using the diameter of the tomato pieces and the outside edge of the pizza base as the basis for measurements. The top of the Slinky collapses, so that the coils slam into each other. That collapse travels down as a wave through the Slinky. The bottom coils remain at rest until the top crashes into them.

And that's the key to understanding how the bottom of the Slinky remains suspended in midair for a short while. This levitation time — approximately 0. Gravity and tension of the spring effectively cancel each other out. Kolkowitz said that one way of understanding this is that on the moon, the weaker gravitational field wouldn't stretch the Slinky as much, so the spring would compress more gently towards the bottom when dropped, taking the same 0. On Jupiter, the stronger gravitational field would stretch the suspended Slinky to a greater degree, so that the spring would have a larger distance to compress.

But the more stretched-out top would snap back faster toward the bottom, resulting in the same levitation time. As Kolkowitz pointed out, however, the Slinky's center of mass — which shifts, but is always located somewhere in between the top and bottom of the toy — still accelerates according to gravity all the way down to the ground from the moment it's released.

So there's no violation of any of Newton's laws or Galileo's observations about falling objects. The levitation time would only increase with a heavier Slinky and decrease if the coils were stiffer. The spring's mass and stiffness, Kolkowitz said, are the only two factors that affect the duration of levitation. Kolkowitz pointed out this levitation effect would occur when any other spring or other elastic, nonrigid object is dropped -- and no object is completely rigid. I would have never thought to measure a slinky.

This would be a challenging math project. I sell slinkys and we just give the circumference. I am happy no one has asked how long they are. It's great that you give the circumference, Arleen, because then you can figure everything else out, this was just a different, fun way to use a circle to measure. Honestly didn't know what a slinky was. Recognised it in the picture. Have to admit the thought of measuring how long it is has never even entered my mind.

Grandmother Diaries. How Long Is A Slinky? By Carol Covin. Metal slinky.