Lab 02 Acceleration Due to Gravity

Acceleration Due to Gravity Names of Participants______________Justin Leopard ______________ Date________8/27/2021 _____ Acceleration Due to Gravity INTRODUCTION : The purpose of this lab is to demonstrate that a free-falling body undergoes constant acceleration (g). The Behr Acceleration of Gravity apparatus can be used to record the fall of a small object on a wax coated paper tape with a reasonable accuracy (< 1%). The resulting tape can be used to analyze uniformly accelerated motion. OPERATION : The Behr acceleration apparatus is diagramed below. The device consists of an electromagnet atop a stand which may be adjusted to the vertical (with the aid of a plumb bob) by three leveling screws at it base. The electromagnet is attached by wires to a power supply, which when energized will suspend the object at the top of the device. Along the length of the stand are two spark wires attached to a synchronous spark timer (which produces a high voltage spark 60 times each second.) When the electromagnet is de-energized the object falls between the spark wires causing a spark to jump from one wire to the other along a metal ring attached to the object. Between the object and one of the spark wires is placed a wax coated tape sensitive to the heat generated by the spark. The dots created on the tape record the position of the falling object 60 times each second allowing the determination of its velocity and acceleration. paper tape for analysis 11

Acceleration Due to Gravity APPARATUS : • Behr acceleration apparatus • synchronous spark timer • wax tape • electromagnetic power supply • meter stick PROCEDURE: 1. Because of the danger associated with the use of high voltage, the instructor will operate the apparatus for the student and provide the wax coated tape for analysis. Examine the tape for skipped dots and ask the instructor how to record them in the Data table. 2. Place the tape on the table and stand a meterstick on edge atop the tape. Align the end of the meterstick with the first clear dot and record the positions (y) of the object in a data table. DO NOT measure the distance between the dots. 3. Subtract consecutive positions to determine the distance the object traveled between measurements ( Δ y = y 2 − y 1 ) and record in the data table. 4. Calculate the average velocity of the object using a time interval (  t) of 1/60 second (v =  y /  t) and record in the data table. DO NOT divide by the time values, divide  y by 1/60 sec (divide by 1/60 = multiply by 60) for each velocity value. 5. In the data table include a column for the time (t) at which the velocity is determined starting with 1/60 second, then 2/60 sec, etc. USE DECIMAL VALUES. 6. Construct a graph of velocity (v) versus time (t). 7. Calculate the slope of the line. This value corresponds to the acceleration of the falling object (see Graph section). 8. Compare your slope with the correct value of g by calculating a % error. 12

Acceleration Due to Gravity DATA: ∆t = ( 1 / 60 ) sec ,g = 981 cm / s 2 n t (s) y (cm)  y (cm) v =  y/  t (m/s) 1 0.000 0 0 1.50 .900 2 0.016 7 1.50 1.50 .900 3 0.033 3 3 2 1.200 4 0.050 0 5 2.10 1.260 5 0.066 7 7.10 2.30 1.380 6 0.083 3 9.40 2.80 1.680 7 0.100 0 12.20 2.80 1.680 8 0.116 7 15 3.30 1.980 9 0.133 3 18.30 3.50 2.100 10 0.150 0 21.80 3.80 2.280 11 0.166 7 25.60 3.90 2.340 12 0.183 3 29.50 4.30 2.580 13 0.200 0 33.80 4.60 2.760 14 0.216 7 38.40 4.80 2.880 15 0.233 3 43.20 5.30 3.180 16 0.250 0 48.50 5.10 3.060 17 0.266 7 53.60 5.80 3.480 13