Rockets continued!

Remember to look for the fish!

PE KE Heat Kinetic You were then asked to come up with an equation for all the energy transferred at the end Energy Transferred You were asked to draw all the energy involved in your rocket – remembering the law of conservation of energy. Is This accurate? OR Intro Activity 1 Notes 1 Notes 2 Activity 2 Closing End

Text in your group’s equation Activity 1 Notes 1 Notes 2 Activity 2 Closing End

So what we were finding the equation for is… What we call Mechanical Energy. It is: The energy possessed by an object due to it’s motion OR its position. So the total energy an object could posses. Ex A basketball It also enables an object to apply a force to another object in order to cause it to be displaced. Ex. Bowling Notes 1 Notes 2 Activity 2 Closing End

The equation for Mechanical Energy is simple: Because Mechanical Energy is basically the total energy an object can possess, both kinetic and potential … it is the sum of potential and kinetic energies, including heat and friction. So ME = PE + KE Notes 2 Activity 2 Closing End

How much mechanical energy is this man using to displace the water in the creek? Activity 2 Closing End

How much mechanical energy is he applying to the surface of the water? Let’s assume that the man weighs 68 kg. Let’s give him the benefit of the doubt and say he was as fast as an Olympic pole vaulter at 8.3 m/s. Let’s assume when he slips, he is only 0.5 m above the water’s surface, How much mechanical energy is he applying to the surface of the water? ME = PE + KE ME = PE = mgh KE = ½mv2 PE = KE = m = m = g = v = h = PE = mgh KE = ½mv2 PE = = = = = ? ? ? 68 kg 68 kg 9.8 m/s2 8.3 m/s 0.5 m 68kg x 9.8m/s2 x 0.5m 666.4 x 0.5 333.2 J ½ x 68kg x (8.3m/s)2 ½ x 68kg x 68.89 34 x 68.89 2342.26J ME = PE + KE PE = 333.2 J KE = 2342.26 J ME = 333.2 J + 2342.26 J = 2675.46 J That means he hit the water with about the same force as a punch! Or the force that a champagne cork leaves a bottle with! Activity 2 Closing End

We’re continuing with your rockets now We’re continuing with your rockets now. But we need to add in the more ‘mathy’ bit Today you in your rocket groups will be finding the total (mechanical energy) of your rockets. Read your instructions carefully! Make sure everyone in your group knows what they will be doing/measuring! Closing End

To the rocket Major Tom! End