How Fast Does a Ball Fall 25 Feet: Physics & Algebra Answer

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To determine how fast a ball falls from 25 feet, the formula d = 16t^2 is used, where d represents distance in feet. The time to fall 25 feet is calculated as t = √(25/16), which simplifies to 1.25 seconds. However, this only provides the time, not the velocity; the velocity can be found by taking the derivative of the distance function, resulting in d'(t) = 36t. The discussion also highlights that the acceleration is constant, leading to the conclusion that the gravitational acceleration is 32 feet per second squared. The conversation raises questions about whether the ball is truly in free fall given the calculations.
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What is the answer to how fast a ball fall's form 25 feet useing the formula d = 16t2 :confused:
 
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d = 16t^2

I assume that this gives the distance in feet. So,

t = \sqrt{25/16}

However you want the velocity of the ball at t = that number above. Can you finish now?
 
physics and algebra

I think the answer is 1 1/4 or 5/4 can you tell me if i am on the right track.? :rolleyes:
 
Yes, that is correct.
 
This is only the time, not the velocity at that time. You still need to find velocity as a function of time. Can you do that?
 
if you find the first derivative of distance as a function of time this wud give you a formula for velocity if acceleration is not constant, in this case it wud be
d'(t) = 36t.
 
FUNKER said:
if you find the first derivative of distance as a function of time this wud give you a formula for velocity if acceleration is not constant, in this case it wud be
d'(t) = 36t.


Judging by the title, I don't think Joseph would know calculus. However, I could be wrong.
 
FUNKER said:
if you find the first derivative of distance as a function of time this wud give you a formula for velocity if acceleration is not constant, in this case it wud be
d'(t) = 36t.
Eh. . . The acceleration is constant. your post should read: "If you find the first derivative of distance as a function of time this would give you a formula for velocity, in this case it would be d'(t) = 36t."
 
The_Brain said:
Judging by the title, I don't think Joseph would know calculus. However, I could be wrong.

Froget calculus; judging by this, "d'(t) = 36t" and the number of times it's been quoted in the last few posts, I don't think anyone here knows what 2*16 is!
 
  • #10
hey,
d = u*t + 1/2 a*t2
=> 25 = 1/2 g*t2 ......(1)
but according to the question
d = 16 t2
or
25 = 16t2.......(2)

comparing (1) and (2)
1/2g=16

g= 32 feet/ second squared ??

or 12.8 metres/second squared ??

was the ball really undergoing a free fall ??
 
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