You are exploring a planet and drop a small rock from the edge of a cliff. In co

Question

You are exploring a planet and drop a small rock from the edge of a cliff. In coordinates where the +y direction is downward and neglecting air resistance, the vertical displacement of an object released from rest is given by

y ? y0 =

gplanett2,

where gplanet is the acceleration due to gravity on the planet. You measure t in seconds for several values of

y ? y0

in meters and plot your data with t2 on the vertical axis and

y ? y0

on the horizontal axis. Your data is fit closely by a straight line that has slope 0.900 s2/m. Based on your data, what is the value of gplanet?    

Explanation / Answer

Since up is positive, the final position of the rock will be negative because it finishes below the starting point at y0=0

. Similarly, the initial velocity is downward and therefore negative, as is the acceleration due to gravity. We expect the final velocity to be negative since the rock will continue to move downward.

intial distance y0=0

V0 IS negative

V2=V02+2a(y-y0)

The acceleration due to gravity on Earth differs slightly from place to place, depending on topography (e.g., whether you are on a hill or in a valley) and subsurface geology (whether there is dense rock like iron ore as opposed to light rock like salt beneath you.)

The precise acceleration due to gravity can be calculated from data taken in an introductory physics laboratory course. An object, usually a metal ball for which air resistance is negligible, is dropped and the time it takes to fall a known distance is measured. See, for example, [link].

Very precise results can be produced with this method if sufficient care is taken in measuring the distance fallen and the elapsed time

WE NEED TO FIND OUT velocity V

WITH HELP OF TIME GIVEN

g planet can be determined

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.