Question

An elevator is moving upward at a uniform speed v0 = 0.40m/s. Suddenly a bolt detaches from the ceiling and starts to fall. How long will it take the bolt fall on the floor of elevator if the height of cabin is h = 2m?

Answer 1

How did u manage to get it

Answer 2

\[y=ut+0.5g(t ^{2})\]
Assume the bolt to be dropping along the Y-axis,with initial velocity 0.4m/s
assume the point of dropping of the bolt to be the origin of the co-ordinate axis,hence y=-2.u=0.4m/s,plug the values into the equation.g=-10m/s2.
though i have a bit of doubt with the velocity,and wat role does it play in the sum!!!

Answer 3

good work dude, welcome to openstudy!

Answer 4

thanks bro, check the question and explain the last line of my comment

Answer 5

will be nice to know. let me try it ur way

Answer 6

how come i get 0.44s

Answer 7

did u take "g" as 10m/s2 or 9.8m/s2

Answer 8

9,8 and i think i may have messe it al up when i got to -5=0,4m/s*t +4,9m/s/s*t^2
how would you continue from there.

Answer 9

i then devided the whole eq by 0.4

Answer 10

sorry the first value is -2 above and not -5

Answer 11

solve the quadratic equation to get the value of t.First multiply the equation by 10(the first equation) -2=0.4t-5t^2
therefore 50t^2-4t-20=0.
25t^2-2t-10=0 now solve it
p.s. take the value of g as 10m/s2 for your own convenience.
Sorry the value should be 1.43seconds and not 0.6 seconds

Answer 12

clear your mind and try to visualize the question as it is appearing in front of you.

Answer 13

Thanks i can apply quadratic formula for that, but doesnt 1.43s seem a long time esp that the lift is also moving up.

Answer 14

i think its okay as the velocity of the lift is not that high,come on 0.4m/s is a small value..