Lab Report 9 Force Table  (23 points) To get credit, always show your work and explain the number of significant digits you use Table 1  (1 point)                                                                                                           Force name Mass (kg) Weight (N) Angle A

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Lab Report 9 Force Table  (23 points)

To get credit, always show your work and explain the number of significant digits you use

Table 1  (1 point)                                                                                                          

Force name	Mass (kg)	Weight (N)	Angle
A	.110	0.882	40
B	.070	0.686	290
E	.115	1.127	183

 

Table 2 (1 point) 

Force name	Mass (kg)	Weight (N)	Angle
A	?	?	40
B	.080	0.784	290
E	.150	1.47	191

 

1. Use the head to tail method to add ???? and ????. Use the magnitudes/directions from Table 1.

Find an appropriate scale factor to convert from kg to cm (either you fill the space provided below or use the attached graph paper). Using your ruler and protractor add the two vectors to find the resultant. Measure the magnitude with a ruler (convert back from cm to kg) and direction with a protractor and record below. (2 points: scale and diagram

 

Scale: 1 kg =  ________  cm 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Magnitude of resultant ????=    _________ cm =  __________   kg =  ­__________   N (1 point)

 

Direction of resultant ????=   ­______  0       (1 point)

2. The equilibrant found in Table 1 by performing the experiment is equal (or close) in magnitude to

the resultant but its direction is opposite to that of the resultant (the difference in angle is 1800).

 

Calculate the percentage error for magnitude between the experimental equilibrant (Table 1)

(consider this value as measured) and resultant (consider this value as standard)

 

% error=|M-S|x 100/S, where M=measured value, S=standard value.        (1 point)

 

 

 

 

 

 

3. Calculate the percentage error for direction between the experimental equilibrant (consider this

value as measured) and resultant (consider this value as standard). Remember that -as they are opposite in direction- you have to add 1800 to the smaller of the two angles to compare them.   (1 point)

 

 

 

 

 

 

 

4. Use component method to add ???? and ????. Use the magnitudes (in Newtons) and directions from Table 1 to find the x and y components of A and B and record them in the first two lines of Table 3. Calculate the x and y components of R and record them in the last line of Table 3.

 

Table 3   (1 point)

	X-component (N)	Y-component (N)
A	Ax=	Ay=
????	Bx =	By =
R	Rx= Ax +Bx=	Ry= Ay+By=

 

 

5. Calculate the magnitude and direction of the resultant ???? using the components Rx and Ry.

Show your calculation and the equations that you used:

 

 

 

 

Magnitude of ????=                                          (unit:                               )             (1 point)

 

 

 

 

Direction of ????=                                            (unit:                               )              (1 point)

6. repeat points 2 and 3 using the magnitude and direction of the resultant obtained with the component method:

 

 

% error for magnitude=                                                                    (1 point)

 

 

% error for direction=                                                                        (1 point)

 

 

 

7. By looking at the two methods used (head to tail or component) to add vectors, what method

agrees best with the experiment? Comment why.   (1 point)

 

 

 

 

 

 

 

8. In Table 2, you know the magnitude and direction of the equilibrant ???? and of ???? . Use the values

in Table 2 and the component method to solve for the magnitude and direction of the unknown

force ????. Record your findings in Table 4.     (1 point)

Table 4

	X-component (N)	Y-component (N)
????	Ex=	Ey =
????	Bx =	By =
????	Ax=-Ex-Bx=	Ay=-Ey-By=

 

 

9. Solve for the magnitude and direction of the unknown force ????. Show the equations you used.

 

 

 

 

 

Magnitude of ????=                                                                                   (unit:                     )   (1 point)

 

 

 

 

 

 

Direction of ????=                                                                                     (unit:                     )   (1 point)

 

 

 

10. Calculate the mass of the unknown object A by dividing the magnitude of the force ????

by g=9.80 m/s2   (1 point)

 

 

 

 

11. Measure the mass of the unknown object using a scale:

 

Mass of the unknown object using a scale =  __150_________   g = ………….. kg    (1 point)

 

12. Calculate the percent difference between the experimental mass (found at point 10.) and the standard mass of the unknown object (found by scale at point 11.).   (1 point)

 

 

 

 

 

 

13. Is the experimental mass accurate? YES NO  Why?   (1 point)

 

 

 

 

 

 

14.  Find the percent difference between the direction of A calculated at point 9. and the known direction (300).   (1 point)

 

 

 

 

 

 

 

15. Is the calculated direction accurate? YES NO  Why?   (1 point)