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Sun 17 Jul, 2005 08:15 pm
A ball with a mass of 0.5kg is dropped from a height of 190cm. The ball is in flight for 5 sec, with gravity acting on it. We can assume that the ball will hit the ground and bounce back to half the initial height. Given this information determine:
a) How long will it take for the ball to come to rest?
b) How fast will the ball be traveling on the intial drop?
What do you mean by "the ball is in flight for 5 sec?" Is that the total time bouncing? Under normal conditions, the ball will reach the ground in well under 5 seconds?
If the ball always rebounds to half the previous height, then theoretically, it never comes to rest. It will, however, travel a finite distance.
The ball is accelerating after it is dropped. At what point do you want the speed?
ok
I don't know what the question is asking for; it was written by my teacher.
i can help you.im not a american,so i might not say the words clear enough.first,the air is acting on it to slow it down,Q=k*l(l represent the length the ball travels in the air) second,the total energy the ball has is E=mgh(h the height),and the time it comes to a rest is the moment all the E is translated into heat.E=Q does it make any sense
An object dropped from 190 cm with negligible air friction will fall for the following amount of time.
s = (1/2)gt^2
(2s/g) = t^2
t = SQRT(2s/g)
g = 9.8 m/s^2 * 100 cm/m = 980 cm/s^2
t = SQRT(2(190 cm)/980 cm/s^2) = SQRT(380/980 s^2)
= SQRT(0.388 s^2)
= 0.6227 sec.
This, not 5 seconds, is the amount of time that it will take the ball to reach the ground. I am not sure what this question means.
When the ball strikes the ground, its speed will be 0.6227 sec(980 cm/s^2) = 610 cm/s.
Sorry, I caught an arithmetic error. 9.8 * 100 = 980 not 9800. Hope the correction isn't too late.
hey
No it isn't too late.
Thanks