Learning Target: - I can explain and calculate forces on objects. - I …mrkillen.weebly.com/.../quest-_asteroid_assault.pdf · 2020-04-27 · Part 5: Ending the Threat Use the information

Quest: Asteroid Assault ***

Copyright © 2020 Daniel Hellmund, Hellmund Science

Learning Target:

- I can explain and calculate forces on objects.

- I can explain and calculate gravitational potential energy.

- I can explain and calculate kinetic energy.

- I can calculate the slope-intercept equation of a line between two points.

In the game world of Aureus Imperium, you and your group notice that a large

asteroid is tearing across the sky with a trail of smoke and flame. It suddenly explodes,

turning into several large fiery boulders. They roar closer to the ground, heading directly

for a large city. In a flash of light they suddenly slow down to a halt and instead float

terrifyingly above the stone buildings of the city!

As you and your group get closer to the city, you spot a a man who appears to be

a wizard of some kind holding up his arms. “This spell has reduced their movement but it

cannot last forever!” he exclaims. “I need your help or the gravitational potential energy

still left in these fragments will destroy the city of Ganymede!” You realize that the net

force on the asteroid fragments must be zero because they stopped accelerating and

remain floating above the city. “My name is Galileo. I will keep these in position as you

identify the safest exit so the people can evacuate! This float spell has

to keep providing a force because gravity is still pulling these

things downward!”

Objective: You will take measurements of the asteroid pieces

to determine the forces, gravitational potential energy, and

kinetic energy related to the asteroid threat. Using this data, you

will then determine the best evacuation location to save the

people of Ganymede!



ASTEROID FRAGMENT OBSERVATIONS: Use this data sheet for the analysis

questions in the quest.

Figure 1: This figure displays the height, in m, above the surface for each asteroid

fragment.

Table 1: This table displays the mass, in kg, of the asteroid fragments.

Asteroid

Fragment

Mass (kg) Asteroid

Fragment

Mass (kg)

A 50 E 200

B 50 F 150

C 100 G 100

D 150 H 200



Part 1: Forces Use the information about the asteroid fragments to complete the net

force questions below. Remember, force is a vector measurement so both magnitude

and direction are needed. Also do not forget about units!

1. Identify the forces acting on each asteroid fragment as they remain suspended above

the city of Ganymede. Label each force and use arrows to indicate direction. If two forces

are the same magnitude, indicate this by placing a line through force arrows that are equal

in strength. Longer arrows indicate stronger forces and shorter arrows indicate weaker

forces. (Note, since this is a fictional example, you can label Galileo’s spell as “float spell

force”)

2. Calculate the strength of the forces acting on each asteroid fragment. You can assume

that the game world is roughly the same size as the Earth, so the acceleration due to

gravity, g, is the same here as it is on the surface of the Earth. Do not forget units!

What equation do you need to use to find the weight, in Newtons?

Asteroid

Fragment

Force of Gravity

(N)

“Float Spell Force”

(N)

A

B

C

D

E

F

G

H



Part 2: Gravitational Potential Energy Use the information about the asteroid

fragments to complete the gravitational potential energy questions below. Do not

forget about units!

1. What is the equation for gravitational potential energy? You can assume that the game

world is roughly the same size as the Earth, so the acceleration due to gravity, g, is the

same here as it is on the surface of the Earth.

2. Complete the chart below. Use figure 1 to determine the height of each asteroid

fragment above the surface. Use this data to then calculate the gravitational potential

energy for each fragment.

Asteroid

Fragment

Mass

(kg)

Height Above the

Surface (m)

Gravitational Potential

Energy (J)

A 50

B 50

C 100

D 150

E 200

F 150

G 100

H 200



Part 3: Kinetic Energy Use the information about the asteroid fragments to

complete the kinetic energy questions below. Do not forget about units!

1. What is the equation for kinetic energy?

2. What is the maximum kinetic energy that each asteroid fragment could have right at

the moment of impact? Use the chart below to help you solve this problem and fill in the

column for the kinetic energy of each fragment in Joules. We will assume that the energy

transformations due to friction and vibrations are zero for this example.

Asteroid

Fragment

Mass

(kg)

Height Above

the Surface

(m)

Gravitational

Potential Energy (J)

Maximum Kinetic

Energy (J)

A 50

B 50

C 100

D 150

E 200

F 150

G 100

H 200

3. We want to compare the energy of each asteroid fragment to the explosive energy in 1

gram of TNT, which is an explosive chemical. 1 gram of TNT has about an explosive

energy of around 4,000 Joules. Around how much TNT would each fragment compare to

if all of its energy was released on impact as an explosion?

Asteroid

Fragment

Max. Kinetic

Energy (J)

Amount of TNT

Equivalent (g)

A

B

C

D

E

F

G

H



Part 4: Evacuation Use the information about the asteroid fragments to complete

the question below. Be sure to write in complete sentences.

1. The city of Ganymede is made of three large castles constructed of stone. We can

identify them as the West Fortress, Center Fortress, and East Fortress, as seen in the

image below. Each fortress was designed to withstand an explosion caused by 50 grams

of TNT in the event of an emergency. If the asteroid fragments were to suddenly drop,

pulled downward only by the planet’s gravity when the spell stops, where should people

evacuate to and why? Be sure to explain your answer with the data you’ve calculated on

the previous pages. If you feel that no location would be safe, explain why none of the

fortress would survive the impact.



Part 5: Ending the Threat Use the information about the asteroid fragments to

complete the questions below. Be sure to write in complete sentences.

1. What field force is responsible for pulling the asteroid fragments downward?

2. What type of stored energy do the asteroid fragments have that make them so

threatening?

3. Identify two ways that this stored energy can be weakened.

4. In most cases, smaller asteroids, meteors, and meteorites never make it to the surface

of the planet because they are so small. Why do these space objects burn up as they move

through the atmosphere? What force do they encounter which causes them to heat up?

5. Realistically, as objects like asteroids fall to the planet, there are other energy

conversions that occur other than the conversion of gravitational potential energy to

kinetic energy. Identify two other energy conversions that occur as these objects fall to

the surface of the planet.

Since Lord Galileo is unable to change the height of each fragment, the citizens of

Ganymede have decided to use the three cannons at the top of each fortress to blast the

fragments into smaller pieces that will have less mass. This should reduce the

gravitational potential energy that each larger fragment has and should spread the pieces

across a wider distance. Unfortunately, these cannons haven’t been used for a while and

have been oxidized. Their range of motion is very limited and has been indicated on the

coordinate plane diagrams with green triangles. The green triangles also display their

range of accuracy.

You will identify the slope-intercept form of a line that connects the cannon’s coordinate

point to the center of each asteroid fragment. The centers of the asteroid fragments are

indicated by white circles. Be sure to use the correct cannon to destroy each fragment!



6. Directions: Identify the slope-intercept equation of a line connecting each cannon

to the proper asteroid fragment center! Be sure to show all work and circle your

final answer for your equation!

Slope-Intercept Equation of a Line Targeting Asteroid Fragment G:

Slope-Intercept Equation of a Line Targeting Asteroid Fragment H:






Slope-Intercept Equation of a Line Targeting Asteroid Fragment E:

Slope-Intercept Equation of a Line Targeting Asteroid Fragment F:






Slope-Intercept Equation of a Line Targeting Asteroid Fragment A:

Slope-Intercept Equation of a Line Targeting Asteroid Fragment B:

Slope-Intercept Equation of a Line Targeting Asteroid Fragment C:

Slope-Intercept Equation of a Line Targeting Asteroid Fragment D:

Documents

Learning Target: - I can explain and calculate forces on objects. - I …mrkillen.weebly.com/.../quest-_asteroid_assault.pdf · 2020-04-27 · Part 5: Ending the Threat Use the information