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part a: A rock is thrown straight upwards from the edge of a bridge with an initial velocity of +35.0 m/s. What will be the velocity of the rock after 2.00 sec?part b: What is the displacement, Δ, at this time?

part a: A rock is thrown straight upwards from the edge of a bridge with an initial-example-1
User Frum
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Part A. We are given that rock is thrown straight upwards from a bridge with an initial velocity of +35 m/s. To determine the velocity after 2 seconds we will use the following equation of motion for the velocity of a body in free fall:


v_f=v_0-gt

Where:


\begin{gathered} v_f,v_0=\text{ final and initial velocities} \\ g=\text{ acceleration of gravity} \\ t=time \end{gathered}

Now, we plug in the values:


v_f=35(m)/(s)-(9.8(m)/(s^2))(2s)

Now, we solve the operations:


v_f=15.4(m)/(s)

Therefore, the velocity after 2 seconds is 15.4 m/s.

Part B. To determine the displacement we will use the following formula:


\Delta y=v_0t-(gt^2)/(2)

Now, we substitute the values:


\Delta y=(35(m)/(s))(2s)-((9.8(m)/(s^2))(2s)^2)/(2)

Solving the operations:


\Delta y=50.4m

Therefore, the displacement is 50.4 meters.

User Joe Pineda
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