PHYS 261 Pre Lab Questions

A cell in an Excel spreadsheet contains $A$5. What does it mean?

Cell A5 is a fixed cell.

Suppose you measure g = 9.7 m/s2 with an uncertainty of \Delta gΔg=0.06 m/s2. Is this consistent with the accepted value g = 9.801 m/s2? Hint: you need to find \varkappaϰ2, see Appendix A.

!!!

You measure the length b of the same side of a block five times and each measurement has an uncertainty of \Delta b=Δb=0.6 mm. What is the uncertainty in the best estimate for b in mm?

0.27

A cart with mass 0.13 kg and velocity 0.54 m/s collides on an air-track with a cart with mass 0.11 kg and velocity -0.74 m/s. What is the final velocity (in m/s) of the two carts if they stick together?

-0.0467

The small angle approximation says that \sin\left(\theta\right)\:\approx\theta (this is true if \thetaθ is measured in radians, but not if \thetaθ is measured in degrees). Find the percentage error \frac{\left(\sin\left(\theta\right)-\theta\right)}{\theta}(sin(θ)−θ)θ this approximation introduces for an angle of 0.11 radians. Note your number should be negative and you need to express it as a percentage (multiply the above expression by 100%).

-0.2015

A mass and spring system has a resonance at fo = 1.007 Hz with a full-width of fFW =0.014 Hz. What is the quality factor Q?

...

Suppose that you measure the length of a pendulum to be L=0.943 m with an uncertainty of \Delta LΔL= 0.007 m. If you use this length and a measured value of the period to find g, what is the uncertainty in g produced by this uncertainty in L? Assume that measured period T has zero uncertainty and the value is equal to Eq (6) with measured L and g=9.801 m/sec2.

0.0728

A cart of mass m = 0.21 kg rides on an air track that is tilted at an angle of 8.2 degrees from the horizontal. What is the magnitude of the total force F (in N) on the cart? (You can use g = 9.8 m/s2)

0.2935

A cart of mass m = 0.57 kg rides on an air track that is tilted at an angle of 3.7 degrees from the horizontal. What is the magnitude of the cart's acceleration (in m/s2) ? (You can use g = 9.8 m/s2)

0.6324

A sonic ranger measures positions x = 0.03 m, 0.207 m, 0.318 m, 0.35 m at times t = 0 s, 0.1 s, 0.2 s, and 0.3 s, respectively. Find the average velocity between t = 0.1 s and t = 0.2 s.

1.11

Using Equation (11), find the theoretical value for the rotation period t for a pendulum bob with orbital radius r = 0.11 m, length L = 0.272 m, yo = 0.02 m and extension arm length ro = 0.02 m. Use g = 9.801 m/s2.

1.1241

You measure the length of the same side of a block find times and find b= 11.0, 11.1, 11.2, 11.2, and 11.3. What is the best estimate for b?

11.16 (take the average)

0.9 radians is equal to how many degrees?

51.5677

Lab 9

Examine relationship between P,V, T and Tair in closed container. Test Ideal Gas Law when temperature is constant (Boyle's law) and when volume is held constant (Charle's law) You will also find absolute zero, the temperature at which the pressure of an ideal gas would be zzero

In Excel, what is the Solver used for? (pick one)

Minimizing or maximizing a cell by varying other cells.

Lab 7

Purpose: Examine the amplitude, resonant frequency, damping time, quality factor adn phase shift of a driven mass-spring oscillator Resonant, large motion when driven at its natural oscillation frequency Quality characterizes loss Q>>1, low loss Zero frequency, phase shift 0 Resonance 90, lag Out of phase 180

Lab 3

Purpose: Study the position, velocity, and acceleration of a body that is acted on by a constant force Use sonic ranger Fine tune the air flow so that it is just enough to enable any glider movement to appear frictionless Ultrasonic motion detector, sonic ranger. Loudspeaker emits a brief pulse of sound that reflects off a screen attached to the cart. The reflected sound returns to the speaker, where it is detected by means of a microphone.

Lab 6

Purpose: The purpose of this experiment is to determine the dependence of the pendulum on the pendulum's length and mass. You will also use measurements to determine g, the acceleration due to gravity Dont' move upper clamp

Lab 5

Purpose: measure an object undergoing centripetal acceleration A body is accelerating whenever the magnitude or direction of its velocity vector is changing

Lab 2

Purpose; Show you how to measure uncertainty in measurements, how to do error propagation, and why it is important to understand the uncertainty in measurements you make If you find the five measurements are identical, you are limited by the resolution of the display (uncertainty 1/3 smallest increment that can be displayed)

Given an x-coordinate and a y-coordinate for a point, which type of chart in Excel will actually plot the point at its Cartesian coordinates? (pick one)

Scatter chart.

Lab 8

Superposition

Lab 1

Teach you basic few things about using Excel to plot and analyze data in 261 labs Only use scatter chart for plotting Solver- minimize or maximize the contents of a target cell by adjusting some other cells that the target cell depends on

Lab 4

The principle of conservation of momentum: The total momentum of a closed system that has no net external force acting on it is constant No net external force, total momentum constant Inelastic collision- Objects bounce off each other, but total kinetic energy before the collision is different from that after the collision Elastic collision- Objects bounce off each other and the total kinetic energy before the collision is the same as after the collision Perfectly inelastic collision- Two objects collide and stick together resulting in the maximum kinetic energy being lost (converted to potential energy or heat in the objects) Drop mass straight down into a cup Small drag, small tilts, some external force

Two carts collide and bounce off each other. If there are no external forces acting on the system, which of the following is true:

The total kinetic energy can change during the collision but the total momentum of the carts must be the same before and after the collision

You measure the lengths of three sides of a block and find a = 5.8 mm, b = 14.6 mm, and c = 15.9 mm with an uncertainty of 0.04 mm in each measurement. What is the uncertainty Dv in the volume of the block in mm3 ?

Use uncertainty

In this lab a periodic force is applied to the cart using:

a spring that is attached to a speaker

A block is measured to have a density \rho=ρ=2.685 g/cm3 with an uncertainty of \Delta\rho=Δρ=0.021 g/cm3. Find\chiχ2 when the measured density is compared to the accepted density of aluminum \rho=ρ=2.70 g/cm3. See Appendix A for how to calculate \chiχ2 .

chi squared= (xi- xtheory)/error in xi

In this lab, the position of a cart will be measured using a sonic ranger. The ranger measures the position by:

emitting an ultrasonic pulse

A block is measured to have a mass M=M=27 g and volume V=V= 5.07 cm3 with an uncertainty of \Delta M=ΔM=0.01 g in the mass and \Delta V=ΔV=0.04 cm3 in the volume. What is the uncertainty in the density in g/cm3?

error propagation

Two carts approach each other, collide, and stick together after the collision. This is an example of what type of collision:

perfectly inelastic collision

What provides the vertical force to balance the force of gravity on the pendulum bob?

tension in the string

To run a macro in Excel, you need to first click on...? (pick one)

the view tab and then click on the macro button.

What is the maximum height y that the pendulum can reach in this experiment?

yo+L