Procedure: 1. Cut a piece of cardstock into the following squares: 4 and 16 . 2. Hang the spring from a horizontal rod that is clamped to a lab stand and place 100g mass on the spring. You want the spring to stretch 6-9cm from the mass.
Description and Theories A. Principles and Theories Used to Obtain our Result An conventional spring, when subjected the weight (w=mg) of an object at one of its terminations, will displace a certain distance, x, with an equal and opposite force, F, being created in the spring of which opposes the pull of the weight. This conventional spring will become significantly distorted if it is subjected to a large enough weight and the force, F, will only be able to return the spring to its original configuration once the burden is removed. The force that will restore the spring to its original configuration is directly proportional to the displacement that occurred. The following equation represents this relationship where k denotes the spring constant or stiffness of the spring, F=-kx Since x symbolizes the displacement or change in the length of the spring the above equation can now be surmised in the following manner, F=mg=-k∆l This new form makes it evident that a linear proportion exists between the plot of F as function of changing in length, ∆, thus confirming the spring does in fact obey Hooke’s Law.
The first part of the procedure is to investigate a = F/m by holding F constant This investigation involving the Atwood machine will investigate the different aspects of a = F/m. The first part of the procedure holds m constant while studying the relationship of F to a by altering the F of the system. Looking at the equation a = F/m, acceleration and force should be directly proportional to one another. F=ka and a=F/k. The second part of the procedure holds F constant and investigates the relationship of a to m by altering the total mass of the system.
The Determination of Keq for FeSCN2+ Purpose: To determine the equilibrium constant Procedure: Part I - Preparing the solution 1)Get 10 test tubes 2)Prep the 5 reference solution test tubes. Mix each solutions using a stirring rod. Standard Volume of .200M Fe(NO3)2 Volume of .00020M KSCN solution Reference Solution #1 8.0mL 2.0mL Reference Solution #2 7.0mL 3.0mL Reference Solution #3 6.0mL 4.0mL Reference Solution #4 5.0mL 5.0mL Reference Solution #5 4.0mL 6.0mL 3)Using he burets transfer the appropriate volumes of each reagent to make the test solutions. Sample .0020M Fe(NO3)2 .0020M KSCN Distilled Water Test Solution #6 5.0mL 1.0mL 4.0mL Test Solution #7 5.0mL 2.0mL 3.0mL Test Solution #8 5.0mL 3.0mL 2.0mL Test Solution #9 5.0mL 4.0mL 1.0mL Test Solution #10 5.0mL 5.0mL 0mL 4) Mix each solution using a stirring rod 5)Measure the temperature of one of the solutions and record. Part II - Spectral Analysis 1)Ensure that the instrument has had time to warm up for 15 min.
The fork was held horizontally over the pipe and the pipe was moved up and down in the water. At the highest pitch of sound the pipe was held in place and the distance between the surface of the water and the top of the pipe was recorded. Data: Data Table 1 | Tuning fork frequency(ƒ),Hz | Length, L(water level to top of pipe) | Diameter of pipe, d | λ=4(L+0.3d) | ExperimentalV= ƒ λ | Room Temperature, Celsius | 384 | | 0.025cm | | | 23 degrees Celsius | Sample Calculation: Theoretical Speed of Sound: v = 331.4 + 0.6TC m/s v= 331.4+0.6(23) v=345.2 Percent Error: % error = experimental value – theoretical value × 100/theoretical value % error = 149.76 – 345.2 × 100/345.2 % error =56.6 Results: Data Table 1 | Tuning fork frequency(ƒ),Hz | Length, L(water level to top of pipe) | Diameter of pipe, d | λ=4(L+0.3d) | ExperimentalV= ƒ λ | Room Temperature, Celsius | 384 | 0.09 m | 0.025m | λ=4(L+0.3d)=4(0.09+0.3x0.025)=4(0.0975)=0.39 | V= ƒ λ=384(0.39)=149.76 | 23 degrees Celsius | Conclusion: There could be many errors that could lead to the percent error calculated. One of which could be the position of either the tuning fork or the pipe. Another could have been the movement of the pipe up and down in the
Student designed practical investigation Title: Atwood’s Machine (Newtons 2nd law of motion). Partner: Qurban Aim: To explore how two different masses act with each other on a pulley and therefore calculate acceleration a (theoretical and experimental) and the Tension T. Hypothesis: When both masses are the same, there should be no acceleration. The larger the ratio between one mass and the other, the higher the acceleration should be. Materials: Pulley, string, mass 1 + 2, ruler, stopwatch, scissors Apparatus: Theory: Since we are trying to find a, the equations we need are: For experimental a: Transposed to: Theoretical a: For tension: where x = displacement u = initial velocity t = time taken = mass 1 = mass 2 Let Method: 1. Set up the apparatus in the diagram above.
Measure outside taper of plug, Fig. 4-2; 5. Calculate the diametral pitch of two suggested gears; 6. Check the pitch of the threads of several given screws, Fig. 4-3; 7.
Friction Objectives: To provide an understanding of the concept of friction. To calculate the coefficient of friction of an object by two methods. Materials: Ramp board: 3 - 4 feet long, 10 cm wide Can of soft drink or item of similar weight Friction block set-PK Protractor Scale-Spring-500-g Tape measure, 3-m Lab notes: Using the wooden block provided in LabPaq, a long board, a can of beans and the 500-g spring scale I will try and determine the force of kinetic friction, N, and the force of static friction, N while pulling the block at a constant speed. I will convert kg-mass to Newtons by multiplying the kg-weight by 9.8 m/s2, i.e., 100 g = 0.1 kg = 0.1 x 9.8 = .98 N. Observations: Mass of block (with can): 3995 kg Weight: 3.91 N Data Table 1: Flat board Flat board Force of Kinetic Friction, N Force of Static Friction, N Trial 1 1.1 0.6 Trial 2 1 0.7 Trial 3 1 0.9 Average 1.03 0.73 Data table 2: Flat board - Block Sideways Mass of block (with can) 3995 kg Weight: 3.91 N Flat Board - Block sideways Force of Kinetic Friction, N Force of Static Friction, N Trial 1 1.3 1.4 Trial 2 1.1 1.5 Trial 3 1.1 1.1 Average 1.2 1.5 Data Table 3: Different surfaces Surfaces tried: Glass surface Force of Kinetic Friction, N Force of Static Friction, N Trial 1 0.4 0.1 Trial 2 0.4 0.1 Trial 3 0.4 0.2 Average 0.4 0.13 Data Table 4: Different Surfaces Surfaces tried: Sandpaper Force of Kinetic Friction, N Force of Static Friction, N Trial 1 2.2 1.5 Trial 2 2.1 1.7 Trial 3 2 1.1 Average 2.1 1.43 Data Table 5: Different Surfaces Surfaces tried: Wood on Carpet Force of Kinetic Friction, N Force of Static Friction, N Trial 1 1.4 1.9 Trial 2 1.5 1.6 Trial 3 1.5 1.7 Average 1.47 1.73 Data Table 6: Raised Board Height Base Length θ max μs Trial 1 .44196 m .71120 m 60 deg 0.62143 Trial 2
Because the resistors i n parallel have a combined resistance of 6 O, y o u f i n d the potential difference across the parallel branch as follows. Given: R = 6 7= 3A ft Unknoivn: V = ? Original equation: V = IR Solve: V = IR = i3 A)(6 ft) = 18 V Therefore, the potential difference across both the top and the bottom branches is 18 V. N o w use this 18-V drop to determine the current i n the 9-ft resistor. Given: F = 18 V R = 9 Unknoivn: 1=1 Original equation: V = IR ft Practice Exercises Exercise 16: Using the diagram, a) f i n d the total resistance i n the circuit, b) Find the total current through the circuit. i s j i loa (oA Answer: a.
Mechanical testing on a piece of epoxy Results: Graph 1, Shows the relationship between the load applied to the epoxy sample and the extension. Graph 1, Shows the relationship between the load applied to the epoxy sample and the extension. A load-extension graph was plotted: Graph 1 shows, how the sample of epoxy extend while the applying force increases. From the graph above, an average value of load over extension is given by the slop. Therefore, calculating the stiffness of the epoxy sample can be found by using the equation bellow (Johnson, et al., 2000).