Kicking Machine Lab

Notes & Calculations

What are we going to do?

You will build a kicking machine that will kick a Ping-Pong ball into a cup lying on its side 12 inches away.

You must use: A pendulum A rubber band A Combo of the two

Content You Must Know

You will be able to calculate: The velocity of your ping pong ball The acceleration of your ping pong ball The force your kicking machine exerts

on the ball The Kinetic Energy the ball possesses as

it is shot forward You will also understand how kinetic

energy and potential energy are related

Now comes notes…

In the following slides we will discuss how to calculate velocity, acceleration, force, and KE.

You will be given a calculations worksheet at

the end of these notes to check your understanding before we move into the lab so I suggest you take notes on these equations.

At the end of this lab you will be given a test over the vocab & calculations we covered in this unit so be prepared!

Velocity

Velocity: the speed and direction of a moving object

To calculate velocity:V = Δ d ÷ ΔtV = (df – di) ÷ (tf –ti)

V

Δd

Δt÷÷

×

Acceleration

Acceleration: the rate of change of velocity (a change in velocity over a period of time)

To calculate acceleration: a = Δv ÷ Δta = (vf – vi) ÷ (tf – ti)

a

Δv

Δt

÷÷

×

Force

Force: a push or pull exerted on an object

Newton’s 2nd Law: states that the acceleration of an object is in the same direction as the net force on an object, and that the acceleration of an object is the net force divided by its mass Basically: F = ma

To calculate force: Force = mass X acceleration

▪ F = ma

Kinetic Energy

Kinetic Energy: energy an object has due to it’s motion

To calculate KE:KE = ½ mass x velocity2

KE = ½mv2

Potential Energy

Potential Energy: energy that is stored due to the interactions between two objects

To calculate potential energy:PE = mass x gravity x heightPE = mgh

Potential energy and Kinetic energy are inversely related This means that when one increases the other

decreases

Law of Conservation of Energy

Law of Conservation of Energy: energy cannot be created or destroyed only transformed into a different form

This means that the ping pong ball sitting in your device will have stored (potential) energy. When your device “kicks” it, it begins to move and thus energy has transformed from potential to kinetic.

Homework

The calculations worksheet is homework and will be due Wednesday at the beginning of class. If you have questions come see me before

then b/c we will not spend class time working on them after today.

If you lose the worksheet do not ask me for another copy. Everything is on my website and you are responsible for printing you another copy if you loose the one I provide you.

Wrap Up

Remember: Calculations due Wednesday Tomorrow you will get with a partner to

design your kicking machine and figure out when/how you will take measurements for your calculations

Sometime mid-unit (while we are working on this lab) there will be a quiz over the material we are covering

At the end, after you have completed the lab, there will be a test over this material!