Speed - the bus jump in the movie

In summary, the bus jump in the movie works because the people on the bus accelerate to thepoint where they jump over the unfinished bridge.
  • #1
Phalon88
2
0
Speed --- the bus jump in the movie!

Homework Statement



In the movie Speed1, a loaded city bus is rigged with an explosive that will detonate and kill everyone aboard if its speed goes below 50 miles per hour. As the bus is moving, the people on board are informed that a bridge ahead in the highway they are on is still under construction and is missing a center segment. They can’t slow down so decide to jump it, so they begin to accelerate.



You must watch a film clip below from the movie to get a good overview of the problem at hand. Some information you need is given in the clip also (observe and listen).

It is then up to you to determine, given the information you hear and observe, if their plan will work.



Q1. Just before the jump, using the info you have and projectile motion (i.e. no air friction) with simple calculations, where would bus be once it reaches other side of unfinished section of bridge (also include a trajectory diagram)?



Q2. What’s about the jump scene is not consistent with the previous scenes?



Q3. Given the info you have, what would be the minimum velocity (magnitude and direction) required to make that jump (include another trajectory diagram and clearly show your calculations)?



Q4. What about the bus might lead you to alter your answers to Q3 a bit for a safe landing?


------


Homework Equations


Vy = Voy + aT ... Vx = Vox + aT
delta y = VoyT + 1/2aT^2 ... Delta x = VoxT + 1/2at^2
delta y = 1/2(voy + Vy)T ...Deta x - 1/2 (vox + Vx)T
Vy^2 = Voy^2 + 2a(delta) ...Vx^2 = vox^2 + 2a(deltax)


The Attempt at a Solution


delta x = 50 ft = 15.24 m
To find T I used V = (delta x)/(delta t)
29.78 m/s = (15.24 m)/t
t=0.511 s
I then used the formula:
delta y = VoyT + 1/2aT^2
I knew that Voy = 0, a = -9.8 m/s^2
so I got -1.279 m = delta y.
So from the negative I know that the bus fell DOWN. so there is no way it made the jump without crashing. If it was > 0 it would have made it just fine.

I'm stumped for question 3...
I have all my components 'figured' out:
Y axis:
Voy = 0 m/s
Ay = -9.8 m/s^2
delta y = -1.279m
T = 0.511s

x axis:
Vox = Vx = 29.78 m/s
Ax = 0
delta x = 15.24 m
T = 0.511 m

I really need help with this. thanks
 
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  • #2


There should be an upslope, so the initial velocity in the y direction is not 0. No value for the angle of the slope is given, but you can work out the minimum value from the speed of the bus and the size of the gap,
 
  • #3


How?
Do you mean I calculate the min velocity needed using the speed and distance of gap?
Or do you mean the angle?
I can't figure out how to solve the angle to get initial V in the y direction, because then I wouldn't know delta y and therefore would only know one side of the triangle --> delta x?
 

Related to Speed - the bus jump in the movie

What is the bus jump scene in the movie "Speed"?

The bus jump scene in the movie "Speed" is a pivotal moment where the main character, Jack Traven, must jump the bus over a 50-foot gap in an unfinished portion of the highway to avoid a bomb detonation.

Was the bus jump in "Speed" realistic?

The bus jump in "Speed" is considered to be somewhat realistic, as it was planned and executed by a professional stunt team. However, there were some special effects used to enhance the scene.

How was the bus jump scene filmed?

The bus jump scene in "Speed" was filmed using a combination of practical effects and CGI. The actual jump was performed using a specially modified bus and a ramp, while the background and explosion were added in post-production.

What was the budget for the bus jump scene in "Speed"?

The budget for the bus jump scene in "Speed" was approximately $5 million. This included the cost of building the set, special effects, and stunt coordination.

Did any accidents occur during the filming of the bus jump scene in "Speed"?

Fortunately, no accidents occurred during the filming of the bus jump scene in "Speed". The stunt team took extensive safety precautions and rehearsed the jump multiple times before the final take.

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