Power Jumping/Hopping - how the bleep does this work?!?!

[Nekira Sudacne]

I forget who I'm quoteing here but. . .

"It's rifts. it dosn't have to make sense"

just go with it. don't get bogged down in realism. it's more fun this way, trust me

[Esckey]

I always thought it was because flight takes alot more out the PA cause it has to fight gravity all the time, while the power jumping was simply that...jumping. The thrusters(and a good running start) throw the thing far ahead but not far off the ground, you land then jump again

Figured a tragectory course would be better then actually flying

[MADMANMIKE]

..Dude, I put a ton of algebraic formulas into my Medieval Governments rules, and I think you're too close to this.

..Really, what's wrong with the notion that the system can generate a better thrust for a short time than a continuous sustained thrust? Think of it like a recharging nuclear powered nitro system. Sustained flight just isn't in the design.

..Why am I still reading this thread? Because you asked a question and still haven't acknowledged any of the answers. That generally raises eyebrows. It's like a freeway accident. WE NEED CLOSURE!!!

-Mike >8]

[Esckey]

While we're on the topic of running and leaping, how far would the Samson beable to go? It's running speed is 150mph. Unless it got changed at somepoint that is

[MADMANMIKE]

..GAH! You've got to be an engineer, and if you aren't you missed your boat!

..Only engineers are that geeky with math!

..I was the leader of the geeks and nerds in my school, but you make us look like dorks. I bow to your superior pocket protector (mine is held together with steel tape).

-Mike >8]

[MADMANMIKE]

..Well, sir, you are a very well adjusted one then. But what about omnicromdilio?

-Mike >8]

[MADMANMIKE]

..Natch.

..You should hang with Shotgunlo. He's an archealogist as well. And there's one thing that makes life much more interesting and less stressful.

..Understand that there is more than our science can explain, both in this world and naturally outside it as well. Let the little things slide and life is so much better.

-Mike >8]

[Drakenred®™©]

well the reason why it works is because you have people who dont work with real physics or weapon systems for a living makeing a game. . . . . .

thats my story and Im sticking with it!

[Mack]

Hey, do you want KS to spend his time writing a new sourcebook, or studying physics?

By the way, does anyone else secretly fear George of The Jungle getting ahold of a Terrain Hopper?

[Drakenred®™©]

Hey, do you want KS to spend his time writing a new sourcebook, or studying physics?

By the way, does anyone else secretly fear George of The Jungle getting ahold of a Terrain Hopper?

[glitterboy2098]

Omni, don't expect the PB staff to put so much thought into stuff. Sometimes you just have to pull an explanation outta yer butt. I mean some guy just "made up" the power hopping movement style and got it published without thinking it through, so why can't you just "make up" a satisfactory explanation for how it works?

Starship Troopers IIRC.

[Qev]

Power jumping works in Rifts because the game designers watched Bubblegum Crisis or somesuch. Physics has nothing to do with it.

[Kalinda]

Power jumping works in Rifts because the game designers watched Bubblegum Crisis or somesuch. Physics has nothing to do with it.

Exactly. It works because it looks cool.

And sometimes that's all that matters.

[Killer Cyborg]

And why not just be able to do a jet-assisted run without the jumps? Why is the running speed limited to 40mph?

Because the armor is designed for jumping.
Kind of like how the running speed for a kangaroo isn't very impressive compared to their jumping speed....
It's all about the design.

[Killer Cyborg]

well the reason why it works is because you have people who dont work with real physics or weapon systems for a living makeing a game. . . . . .

thats my story and Im sticking with it!

The best answer I've heard so far.

Physics don't change just because you can't explain how something works.

Generally, I chalk most stuff like this up to "Highly Advanced Science That Seems Incomprehensible To Our Primitive 20th Century Minds".

[Qev]

Generally, I chalk most stuff like this up to "Highly Advanced Science That Seems Incomprehensible To Our Primitive 20th Century Minds".

"Any sufficiently advanced technology is indistinguisable from bad game design?"

(apologies to Arthur C Clarke...)

[Killer Cyborg]

Generally, I chalk most stuff like this up to "Highly Advanced Science That Seems Incomprehensible To Our Primitive 20th Century Minds".

"Any sufficiently advanced technology is indistinguisable from bad game design?"

(apologies to Arthur C Clarke...)

[Shiva7]

T-21

Weight: 100 lbs (45.5 kg) + pilot:~175lbs (79.5 kg) = 275 lbs (125 kg)
Height: 7 ft (2.13 m)
Jump Height: 15 ft (4.57 m)
Assisted Jump Height: 200 ft (60.96 m)

Jump Speed: a = -9.8 m/s², d = 4.57 m, vf = 0 m/s, t = ?

vf² = vo² + 2ad
vo² = -2(-9.8 m/s²)(4.57 m) = 89.572
vo = 9.464 m/s (21.18 mph/34.07 kmph)

Jump Force: m = 125 kg, d = 1.065 m, vo = 0 m/s, vf = 9.464 m/s, a = ?

a = vf²/2d = (89.572 m²/s²)/2.13 m = 42.05 m/s²
F = ma = 5,256.6 N

Assisted Jump Speed: a = -9.8 m/s², d = 60.96 m, vf = 0 m/s, t = ?

vf² = vo² + 2ad
vo² = -2(-9.8 m/s²)(60.96 m) = 1,194.76 m²/s²
vo = 34.565 m/s (77.34 mph/124.43 kmph)

Assisted Jump Force: m = 125 kg, d = 1.065 m, vo = 0 m/s, vf = 34.565 m/s, a = ?

a = vf²/2d = (1,194.76 m²/s²)/2.13 m = 560.92 m/s²
F = ma = 70,114.9 N

Jet Force = 70,114.9 N - 5,256.6 N = 64,858.3 N

Power Jumping Arc: [Length: 300 ft (91.44 m), height: 25 ft (7.62 m)]

vf = 0 m/s, a = -9.8 m/s², d = 7.62 m, vo = ?, t = ?

vf² = vo² + 2ad
vo² = -2(-9.8 m/s²)(7.62 m) = 149.34 m²/s²
vox = 12.22 m/s (27.34 mph/43.99 kmph)

t = vo/a = (12.22 m/s)/(9.8 m/s²) = 1.247 s

voy = d/t = 45.72 m/1.247 s = 36.66 m/s (82.03 mph/131.98 kmph)

vo = (vox² + voy²)^(1/2) = 38.65 m/s (86.47 mph/139.12 kmph)

Obviously the stats given by the book for the typical jump arc, provide a max velocity of 86.47 mph, but a horizontal travel velocity of only 82.03 mph (about half the stated speed).

If we take the vertical assisted jump velocity of 77.34 mph and assume the take off angle is the same as the stated arc, the the horizontal velocity would be about 73.37 mph plus running speed of 40 mph for a total attainable horizontal travel speed of 113.37 mph (182.41 kmph). Closer, but still shy of the stated speed of 170 mph (274 kmph).