Question

USE GUESS METHODI drop a penny from the top of the tower at the front of Fort High School and it takes 1.85 seconds to hit the ground. Calculate the velocity in m/s after 1.10 seconds of freefall and calculate the velocity at impact in mi/hr.

Answer 1

Given:

time of 1.85 seconds,

time of 1.10 seconds,

initial velocity = 0,

gravity acceleration = 9.8 m/s².

Unknown:

velocity V1 at t = 1.1 s (in m/s),

velocity V2 at t = 1.85 s (in mi/hr).

Equations:

`V=V_0+a\cdot t`

Setup:

(1 m/s is equal to 2.237 mi/hr)

`\begin{gathered} a=g=9.8\text{ m/s}^2 \\ V_1=0+9.8\cdot1.1_{} \\ V_2=(0+9.8\cdot1.85)\cdot2.237 \end{gathered}`

Solve:

`\begin{gathered} V_1=9.8\cdot1.1 \\ V_1=10.78\text{ m/s} \\ \\ V_2=9.8\cdot1.85\cdot2.237 \\ V_2=40.56\text{ mi/hr} \end{gathered}`