Freefall, is the answer really 20 ?

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In summary, a lead ball is dropped into a lake from a diving board 5.0 m above the water and sinks into the bottom with a constant velocity for 3 seconds before hitting the bottom of the lake. Using the equation Vf^2 - Vi^2 = 2as, the velocity is calculated to be 9.89 m/s. However, there is confusion about the time it takes for the ball to hit the water and whether it is exactly 3 seconds. The final depth of the ball can be found by multiplying the velocity by 3, giving an answer of 29 meters. However, there is discrepancy in the given answer of 20 meters.
  • #1
EvilBunny
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Homework Statement



A lead ball is dropped into a lake from a diving board 5.0 m above the water. After entering into the water it sinks into the bottom with a constant velocity which it hit the water for 3 seconds. and hits the bottom of the lake. How deep is the late ?

Homework Equations


Vf ² - Vi ² = 2as


The Attempt at a Solution



Well I just used this equation and I get a velocity of 9.89 which I find odd. I think it should take less then 1 second to hit the water.

I get an answer of 29 meters by finding out the velocity and multipling by 3 seconds.
Altho in the answers it says 20.
 
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  • #2
You should be right. It didn't say 2 seconds?
 
  • #3
did you post the question exactly? Is the 3 seconds after it hits the water? I'm confused by this part:

"which it hit the water for 3 seconds. and hits the bottom of the lake"
 
  • #4
show more steps, i don't like the equation you used
 

Related to Freefall, is the answer really 20 ?

1. What is freefall?

Freefall is the motion of an object falling under the influence of gravity, with no resistance or external forces acting on it.

2. How does gravity affect freefall?

Gravity is the force that pulls objects towards the center of the Earth. In freefall, gravity causes the object to accelerate towards the ground at a rate of 9.8 meters per second squared.

3. Why is the answer for freefall always 20?

The answer of 20 refers to the acceleration due to gravity, which is always 9.8 meters per second squared. This value is often rounded to 10 for simplicity, resulting in the answer of 20.

4. Is there a way to calculate the exact answer for freefall?

Yes, the exact answer for freefall can be calculated using the formula: distance = 1/2 * acceleration * time squared. However, in most cases, the answer of 20 is used for simplicity.

5. Does air resistance affect freefall?

Air resistance can affect freefall, as it is a force that opposes the motion of falling objects. However, in most cases, it is negligible and can be ignored in calculations.

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