What's an explosion? (a kaboom kahoot)

What is an explosion?

• rapid expansion in volume

• huge release of energy

• hot pressurized gas

Answer explanation

Given energy, molecules that were once chill with being in a small space together, now want their own personal space bubbles. So they fly away from each other at high speeds, releasing energy, and pushing surrounding air molecules really close together to create a blast/shock wave.

What part of the blast comes first?

• debris/shrapnel

• heat

• blast wind

• blast wave

Answer explanation

Traveling faster than sound, the blast wave reaches the areas surrounding the explosion first

You can see the compressed air molecules of the wave in the picture!

Explosions are made up of SHOCK waves that are ____ than SOUND waves

• faster

• slower

• the same as

Answer explanation

Shock waves can move FASTER than the speed of sound, making them supersonic. The high kinetic energy is what makes explosions, and not your Spotify playlist, hot and dangerous. Unless you're listening to Ke$ha

If the speed of sound in air is 343 m/s, how fast do you think TNT detonates?

• 530 m/s

• 1,420 m/s

• 6,900 m/s

• 8,750 m/s

Answer explanation

8,750 m/s is the speed at which another supersonic explosive known as C-4 detonates at

Nitroglycerine, the active ingredient in dynamite, detonates at 7,700 m/s

Explosions are more dangerous in open or closed areas?

• open

• closed

• neither, they're equally dangerous

Answer explanation

Closed. Blast waves from an explosion can bounce off of solid objects, in many directions, until it runs out of energy. Open spaces let the wave pass in one direction

ID the movie mistake

• her hair isn't moving -- where's the wind?

• her sunglasses do not go with her top

• the tree isn't on fire

Answer explanation

Now we know that a blast wave is made up of pressurized air molecules traveling outward. But rapid formations of high-pressure gas leave an area of low-pressure gas right next to them. This creates wind

the magnitude of a blast wave depends on...

• type of explosive

• distance from point of origin

• amount of explosive

• how hot the explosion gets

Answer explanation

The heat of an explosion is actually felt after the blast wave, so heat doesn't have to do with the wave's magnitude.

What would this sound like?

• KaBOOOM!!!

• ...

• BLAM!

• pop!

Answer explanation

Unfortunately, most sci-fi movies have been lying to you. Explosions in space would be pretty silent because our perception of sound comes from the vibrations of air molecules around us, and there aren't a lot of air molecules in space.