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abruno
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A hockey puck slides off the edge of a table with an initial velocity of 20.0 m/s. The height of the table above the ground is 2.0m. What is the magnitude of the velocity of the puck just before it touches the ground? I know the answer is 21m/s but can you show me how?
 one year ago
 one year ago
abruno Group Title
A hockey puck slides off the edge of a table with an initial velocity of 20.0 m/s. The height of the table above the ground is 2.0m. What is the magnitude of the velocity of the puck just before it touches the ground? I know the answer is 21m/s but can you show me how?
 one year ago
 one year ago

This Question is Open

BTaylor Group TitleBest ResponseYou've already chosen the best response.1
Kinematics shows us that the horizontal and vertical components of the motion are separable. The horizontal velocity (in this case, 20.0 m/s) is constant. The vertical velocity changes because of gravity's acceleration. The vertical velocity can be found with this equation (only because the initial vertical velocity is zero):\[v_f = \sqrt{2gh} = \sqrt{2 \times 9.8 \times 2} \approx 6.2\]Now that we know the vertical and horizontal components, we can find the resultant velocity: dw:1368495720450:dw Using Pythagorean's theorem: \[v_f = \sqrt{v_x^2 + v_y^2} = \sqrt{20^2 + 6.2^2} \approx 20.94\] So your answer is 20.94 m/s, which does indeed round to 21 m/s.
 one year ago

abruno Group TitleBest ResponseYou've already chosen the best response.0
You are awesome! Thanks!
 one year ago
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