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Energy Transformations

Akoranga 4 Mahi Tuatahi 🔗

  1. Open Quizizz on your device (phone or laptop)
  2. Get ready to play!

https://quizizz.com/admin/quiz/5c110c53e13e0f001a388fbb/meteors-comets-and-asteroids

Ngā Whāinga Ako 🔗

  1. Recall key terminology around meteorites
  2. Describe factors that affect the size and shape of an impact crater

Write the date and ngā whāinga ako in your book

Pātai 🔗

Whakatika 🔗

Energy cannot be created or destroyed, it can only be transferred or transformed.

Source

Pātai: Describe These Transformations 🔗

  1. Miles is playing football and kicks the ball into the air upfield to a striker.
  2. Toby gets up in the morning to go for a run. He eats three Weet-Bix before he goes.
  3. Phoenix goes bungee jumping near Wanaka.

Write the answers in paris, in your book.

Whakatika 🔗

  1. Kinetic (foot) –> elastic + sound + heat –> kinetic + gravitational (ball) –> kinetic + sound + heat + pontential as the striker catches the ball.
  2. Chemical –> potential + kinetic as he gets up –> kinetic as he runs
  3. Potential –> kinetic –> elastic potential at the bottom

Pātai: Energy in Meteors 🔗

What energy transformations do meteoroids undergo as they fall towards and onto a planet/moon?

Source

Whakatika 🔗

Source

Pātai 🔗

What happens to the rest of the kinetic energy if the meteor doesn’t completely break up in the atmosphere?

Source

Whakatika 🔗

Source

The kinetic energy is transferred into the ground, creating an impact crater and throwing out debris!

Gravitational Potential Energy / Pūngao tō ā-papa 🔗

The potential an object has to fall in a gravitational field.

\begin{aligned} E_{p} &= mass \times gravity \times height \newline E_{p} &= m \times g \times h \end{aligned}

Pātai: What can we change about a meteoroid to give it more gravitational potential energy?

Whakatika 🔗

  1. Increase its mass
  2. Increase its height (distance away from Earth) in the gravitational field

Source

Kinetic Energy / Pūngao Neke 🔗

Energy an object in motion has

\begin{aligned} Energy &= \frac{1}{2} mass \times velocity^{2} \newline E &= \frac{1}{2}m \times v^{2} \end{aligned}

Pātai: What can we change about a meteorite to give it more kinetic energy?

Whakatika 🔗

  1. Increase its mass!

\begin{aligned} E &= \frac{1}{2} \times 10 \times 10^{2} &&= 500J \newline E &= \frac{1}{2} \times 20 \times 10^{2} &&= 1,000J \end{aligned}

  1. Increase its velocity (has a greater effect)!

\begin{aligned} E = \frac{1}{2} \times 10 \times 10^{2} = 500J \newline E = \frac{1}{2} \times 10 \times 15^{2} = 1,125J \end{aligned}

Akoranga 5 Mahi Tuatahi 🔗

  1. Brainstorm some characteristics of a crater that could change depending on the energy of the impact?

Whakatika 🔗

Conservation of Energy 🔗

Typically to increase the energy of an impact in a simulation we increase the height that it is dropped from, thereby giving it more gravitational potential energy to be converted to kinetic energy (increasing its impact velocity).

\begin{aligned} E_{p} &= E_{k} \newline m \times g \times h &= \frac{1}{2}m \times v^{2} && \text{Mass cancels out} \newline g \times h &= \frac{1}{2} \times v^{2} && \text{Re-arrange for v} \newline 2 \times g \times h &= v^{2} \newline \sqrt{2 \times g \times h} &= v \end{aligned}

Theoretical vs Real-World 🔗

\begin{aligned} v = \sqrt{2 \times g \times h} \end{aligned}

Source

Pātai 🔗

\begin{aligned} v &= \sqrt{2 \times g \times h} \newline E_{k} &= \frac{1}{2} \times m \times v^{2} \end{aligned}

  1. Calculate the impact speed of an object dropped from $1m$
  2. Calculate the impact speed of an object dropped from $2m$
  3. Calculate the impact speed of an object dropped from $5m$
  4. Calculate the impact kinetic energy of a $10kg$ object travelling at $3000ms^{-1}$
  5. Calculate the impact kinetic energy of a $750kg$ object travelling at $5000ms^{-1}$

Ngohe: Google Earth Tour 🔗

Source

  1. Open Google Classroom and find the Google Earth link
  2. Follow through the tour – make sure to read more on each stop!

Ngohe: Quizizz 🔗

https://quizizz.com/admin/presentation/5fcd762e8e241c001b80de03/meteoroids-meteor-or-meteorites