PHYS261 Cumulative Lab Questions and
Answers| Latest Update
Without using a thermometer, how can you establish a temperature of 100 degrees C? Correct
Ans-Boil water
Use the thermometer to accurately measure room temperature and estimate the uncertainty in this
measurement. Correct Ans-About 20 degrees Celsius
Uncertainty:
Using Charles Law Apparatus: deltaT=0.003*T+.02
Using thermometer: deltaT=0.5 or 0.25 of smallest division
What does absolute zero temperature mean? Correct Ans-The temperature at which the
pressure of an ideal gas would be zero (0 Kelvins)
Using the Charles' Law apparatus, a student finds pressures of 760, 840, 950 mm of Hg at
temperatures of 26, 57, and 100 degrees Celsius. Use the spreadsheet to make a plot of P versus
T and find the slope of the resulting straight line. Does the data agree with Charles' Law? Briefly
explain. Correct Ans-Plot in excel. Linear relationship-->P=C*T
Using the ruler, and without using the vernier calipers, estimate how precisely you can measure
the length of one of the sides of one of the blocks. Correct Ans-To within 0.5 mm or 0.25 mm
,Suppose you use the scale to measure the mass of the brass block. What is the uncertainty in the
mass? Correct Ans-0.033 g
If a 1 cm block is placed under one leg of the air track, what is the tilt angle of the air
track? Correct Ans-0.006667 radians
asin(0.01/1.5)
A cart starts at X=0.5 m with an initial velocity of 1 m/s heading up the airtrack. Assuming that
the airtrack is tilted at 0.01 radians, use the spreadsheet to calculate and plot the position versus
time and the velocity versus time of the cart. Correct Ans-d=d0+v0*t+(a0*t^2)/2
a0=g*sin(theta)
v=vi+a0*t
A cart with mass 0.3 kg and velocity 0.1 m/s collides on an air track with a cart with mass 0.4 kg
and velocity -0.2 m/s. If the final velocity of the first cart is -0.1 m/s after the collision, what is
the velocity of the second cart? Correct Ans--0.05 m/s
mv=mv
Using the ruler, how precisely can you measure the length of the pendulum? Correct Ans-0.5
mm or 0.25 mm
, Measure the time for 20 swings of the pendulum. What is the period? Correct Ans-Use
Logitech.
Period=time for one swing
Why is it important to keep the angle small in this experiment? Explain. Correct Ans-If the
angle is small, the small angle approximation allows for tau=-mgLtheta
To what uncertainty can the drive frequency be determined in this experiment? Correct Ans-
About 0.00033 Hz because it can measure down to 1 mHz
Measure the resonant frequency of this system. Correct Ans-Find period (time between two
maximums), then take inverse.
Suppose that you wanted to increase the quality factor Q of the system, what could you
do? Correct Ans-The mass could be increased.
How is the spacing between nodes of a standing wave related to the wavelength? Correct Ans-
Wavelength=2*spacing between two nodes
How is the velocity of the wave related to the mass hanging off the end? Correct Ans-
v=sqrt((mg)/mu)
How precisely can you measure temperature in the Charles' Law apparatus? How precisely can
you measure the pressure? Correct Ans-.01 degrees Celsius
Answers| Latest Update
Without using a thermometer, how can you establish a temperature of 100 degrees C? Correct
Ans-Boil water
Use the thermometer to accurately measure room temperature and estimate the uncertainty in this
measurement. Correct Ans-About 20 degrees Celsius
Uncertainty:
Using Charles Law Apparatus: deltaT=0.003*T+.02
Using thermometer: deltaT=0.5 or 0.25 of smallest division
What does absolute zero temperature mean? Correct Ans-The temperature at which the
pressure of an ideal gas would be zero (0 Kelvins)
Using the Charles' Law apparatus, a student finds pressures of 760, 840, 950 mm of Hg at
temperatures of 26, 57, and 100 degrees Celsius. Use the spreadsheet to make a plot of P versus
T and find the slope of the resulting straight line. Does the data agree with Charles' Law? Briefly
explain. Correct Ans-Plot in excel. Linear relationship-->P=C*T
Using the ruler, and without using the vernier calipers, estimate how precisely you can measure
the length of one of the sides of one of the blocks. Correct Ans-To within 0.5 mm or 0.25 mm
,Suppose you use the scale to measure the mass of the brass block. What is the uncertainty in the
mass? Correct Ans-0.033 g
If a 1 cm block is placed under one leg of the air track, what is the tilt angle of the air
track? Correct Ans-0.006667 radians
asin(0.01/1.5)
A cart starts at X=0.5 m with an initial velocity of 1 m/s heading up the airtrack. Assuming that
the airtrack is tilted at 0.01 radians, use the spreadsheet to calculate and plot the position versus
time and the velocity versus time of the cart. Correct Ans-d=d0+v0*t+(a0*t^2)/2
a0=g*sin(theta)
v=vi+a0*t
A cart with mass 0.3 kg and velocity 0.1 m/s collides on an air track with a cart with mass 0.4 kg
and velocity -0.2 m/s. If the final velocity of the first cart is -0.1 m/s after the collision, what is
the velocity of the second cart? Correct Ans--0.05 m/s
mv=mv
Using the ruler, how precisely can you measure the length of the pendulum? Correct Ans-0.5
mm or 0.25 mm
, Measure the time for 20 swings of the pendulum. What is the period? Correct Ans-Use
Logitech.
Period=time for one swing
Why is it important to keep the angle small in this experiment? Explain. Correct Ans-If the
angle is small, the small angle approximation allows for tau=-mgLtheta
To what uncertainty can the drive frequency be determined in this experiment? Correct Ans-
About 0.00033 Hz because it can measure down to 1 mHz
Measure the resonant frequency of this system. Correct Ans-Find period (time between two
maximums), then take inverse.
Suppose that you wanted to increase the quality factor Q of the system, what could you
do? Correct Ans-The mass could be increased.
How is the spacing between nodes of a standing wave related to the wavelength? Correct Ans-
Wavelength=2*spacing between two nodes
How is the velocity of the wave related to the mass hanging off the end? Correct Ans-
v=sqrt((mg)/mu)
How precisely can you measure temperature in the Charles' Law apparatus? How precisely can
you measure the pressure? Correct Ans-.01 degrees Celsius
