How Long Does It Take for a Dart to Reach the Board from 1.9m?

AI Thread Summary
The discussion focuses on calculating the time it takes for a dart thrown horizontally from a height of 1.9 meters to reach the dartboard, along with determining its horizontal velocity. The vertical motion is analyzed using the equations of motion, considering gravitational acceleration of 9.81 m/s². The user attempts to solve for the initial velocity but encounters confusion regarding the signs in the equations. The calculations involve determining the vertical distance fallen and the corresponding time taken for the dart to hit the board. Ultimately, the discussion highlights the importance of correctly applying gravitational acceleration in motion equations.
faisal
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''A DART LEAVES THE THROWER HAND HORIZONTALLY AT A height of 1.9m above the ground, calculate the time taken by the dart to reach the board and the horizontal velocity at which the dart left the throwers hand.''
this is what iv worked out
x-0.4
u-?
v-0
a-0
t-?
i than went onto finding the verticle acceleration
x-0.4, u-?, v-0. a-9.81, t-?
v^2=u^2+2ax
v^2-u^2=2ax
v^2-v^2-u^2=2ax-v^2
u^2=2ax-v^2
-u^2=2ax-v^2
2x9.81x0.4=7.84
i than found the square root of 7.84 however it was wrong, since it was -u^2
 
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we are talking on Earth here? if so, what acceleration do we all experience on earth...the acceleration due to __________
 
Gravity! :)
 
Faiza said:
Gravity! :)

... ;-)
 

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