I need help with this question and could I see it worked out,so I know how you d
ID: 1727110 • Letter: I
Question
I need help with this question and could I see it worked out,so I know how you did this. A rock is dropped off the side of a bridge and hits the waterbelow 4s later. a. What was the rock's velocity when it hit thewater? I got 9.8 x 4 = 39.2 m/s ( Is thiscorrect?) b. What was the rock's average velocity as itfell? c. What is the height of the bridge above thewater? I am very confussed. Thank you. I need help with this question and could I see it worked out,so I know how you did this. A rock is dropped off the side of a bridge and hits the waterbelow 4s later. a. What was the rock's velocity when it hit thewater? I got 9.8 x 4 = 39.2 m/s ( Is thiscorrect?) b. What was the rock's average velocity as itfell? c. What is the height of the bridge above thewater? I am very confussed. Thank you.Explanation / Answer
Time of fall, t = 4 s Initial velocity, U = 0 m/s (a) Velocity of rock on hitting the water, V = U- g t = 0 - 9.8 * 4 = - 39.2 m/s ( here '-' indicate downward direction ) (b) Average velocity, Vav = ( U + V ) / 2 = - 19.6 m/s ( here '-' indicate downward direction ) (c) Height of the bridge above the water, H = ( 1/2) g t 2 = 0.5 * 9.8 * 4 2 = 78.4 m