Vertical Motion Scenario Solving for Velocity

AI Thread Summary
The discussion revolves around a physics problem involving two agents, one of whom accelerates after a delay while the other jumps from a height. The main challenge lies in calculating the final velocity and distance traveled by Agent 001, considering his 0.75-second reaction time. The initial attempts to solve the problem using standard equations yielded incorrect results, prompting the user to seek alternative methods for accuracy. Ultimately, the solution was found by adjusting the starting point to account for the reaction time and including an initial position. The thread concludes with the successful resolution of the problem after collaborative input.
cassc94
Messages
2
Reaction score
0

Homework Statement


Agent 001 is on another mission... to stop Mr. LateforClass's ploy to threaten mankind with a moon based "Space" Laser, which is powered by rezigrene batteries. 001 tracks LFC for several months and finally finds him on the 2nd floor of an old run down factory. LFC jumps out of a window to escape from 001, and accelerates at 10m/s^2 w/ his rocket pack (initial velocity is 0m/s). 001 is directly 20m below LFC, when he too fires his rocket pack after his 0.75s reaction time, and gives chase (initial velocity 0m/s, acceleration of 16m/s^2). Calculate the final velocity of 001 when he catches LFC and also find the distance 001 travels.


Homework Equations


V2^2 - V1^2 = 2(a)(d)
d = (v1)t + 0.5(a)(t^2)
d = (v2)t - 0.5(a)(t^2)


The Attempt at a Solution



I solved the same question except with different accelerations/times/velocities. Earlier i solved it with a table showing their distance over each second, which helped me find the time of their equal distance. This scenario is more difficult particularly because of his 0.75second reaction time. I thought to construct a graph to find the time, but when i plugged it into the equation as seen on my page i get 124...which is not even near what my graph indicates.

My graph shows that they intersect at about 154m of height after about 4.7 seconds.

Can anyone see what I am doing wrong?

Is there any other way i can get a more accurate answer for either time or distance? I can't use the above equations to solve anything without one or the other..
 

Attachments

  • 20130213_145511.jpg
    20130213_145511.jpg
    23.8 KB · Views: 415
  • 20130213_151848.jpg
    20130213_151848.jpg
    30.2 KB · Views: 442
Physics news on Phys.org
I can't use the above equations to solve anything without one or the other..
You can, if you start at t=0.75 seconds, for example. In addition, you need an initial position there.
 
I solved it! Thanks for the thought though!
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top