SKATE PARK PHYSICSPhysics is PhunSkate Park Physics

Before we get started lets go to the link below and open the skate park sim

http://phet.colorado.edu/en/simulation/energy-skate-park-basics

FrictionSet the grid in the background.1. Explore what would happen with no

frictiona. How does the skaters starting point

compare with the ending point?b. What happens when you increase

the friction?c. Find the friction for the skater.

EnergyCheck the square for the pie chart. Notice the colors-thermal, kinetic, potential.

1. How does the kinetic energy relate to potential energy?

2. Why is thermal energy absent?3. What happens when we increase friction?4. How does the pi chart effectively communicate

the law of conservation of energy.

Energy Cont.Check the bar graph. Run the program noticing how the energy

is shown on the bar graph.

SpeedCheck the box for the speedometer.1. How would you describe the speed at

various points on the track?2. Where is the speed the greatest?

Describe the types of energy at this point.

3. Where is the speed the least? Describe the types of energy at this point.

Further ObservationsTake a few minutes and try the other track options. Observe the speed, energy. Vary the friction of the skateboarder.

How are speed and energy related?

Kinetic and Potential Energy

The formula for kinetic energy is mv2.

The formula for potential energy is mgh.

Because of conservation of energy mv2 + mgh on a frictionless track is equal throughout the track. The mass, the acceleration of gravity are constant and the velocity and the height of the skater are variables.

If a 40 kg skater is 3 meters off the ground at the beginning of his skate what is his velocity at the bottom of

the hill?

The equation would look like this

mv2 TOP+ mghTOP = mv2

TOP + mghTOP

(40kg)(0 )2 +(40kg)(9.8 )(3m)= (40kg)v 2+(40kg)(9.8)(0m)

Solve for the velocity

Do you where do you think the skater is located for each of the

following graphs? Is friction turned off or on?

Draw a bar chart for each position.Assume the friction is turned off.Assume A is the starting point.

A

B

C

D

Draw a bar chart for each position.Assume the friction is turned on.Assume A is the starting point.

A

B

C

D

Make your own skate park.

Now create your own skate park. How does the law of conservation of energy influence your considerations.

Physics is Phun

Tennessee Standards Check 3231.1.17 Investigate the definitions of

force, …, kinetic energy, and potential energy.Kinetic Energy: EK = 0.5mvPotential Energy: EP = mg∆h.

SPI.3231.1.6 Given the static and kinetic friction coefficients (μs and μk);

select the appropriate coefficient of friction and calculate

the force necessary to move the object.