Find time given initial velocity, distance and acceleration.

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Homework Help Overview

The problem involves a scenario where an object (an anvil) is dropped from a certain height while being influenced by gravity. The context includes initial velocity, distance, and acceleration, specifically focusing on the time it takes for the anvil to hit the ground and its velocity just before impact.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the application of the quadratic formula to solve for time and express concerns about the validity of negative solutions. There is also a focus on calculating the final velocity and the implications of sign conventions in the context of the problem.

Discussion Status

Participants have shared their calculations and results, noting discrepancies in the interpretation of signs in the final velocity. There is an ongoing exploration of the quadratic solutions and the implications of initial conditions on the results.

Contextual Notes

There is a mention of the gravitational acceleration value and the initial conditions of the problem, which may influence the calculations. The discussion reflects on the assumptions made regarding the direction of motion and the resulting signs in the equations used.

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Homework Statement



Coyote falling down with a parachute holding an anvil at 10m/s. At 50m he drops the anvil.

A) How long does it take for the anvil to hit the ground?
B) what is the velocity of the anvil right before it hits the ground?

Homework Equations



X= Xo + V0T+1/2A(T^2)

g= 9.8 m/s^2

The Attempt at a Solution



50m = 10m/sT + 4.9m/s^2T^2

i use the quadratic equation and got t= 1.14 and -2.143

however i know this is wrong since i can not get a negative second and it seen like the "s" cancel out and you got T = a number without second.

also i know the answer is 2.33 s for (A) but want to know how to get that answer.
 
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Seems like you've done everything correctly except solving the quadratic. I get 2.333 and -4.37381 for my solutions. Or at least my calculator does...
 
Bhumble said:
Seems like you've done everything correctly except solving the quadratic. I get 2.333 and -4.37381 for my solutions. Or at least my calculator does...

yeah i actually re did the quadratic i also got 2.33 and -4.373
 
ok for

B) what is the velocity of the anvil right before it hits the ground?

i use V = Vo + AT and got V= 10m/s + 9.8 m/s^2(2.33s) got V =32.9 m/s

However the answer is in negative (as in -32.9 m/s) what did i do wrong to miss the negative sign?
 

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