physics 1401 lab exam
Which result can be derived from this experiment?
. Pressure and volume have an inverse relation
During the lab experiment, the velocity of sound in dry air at 0C is measured and found to be 333.1 m/s. The accepted value for the velocity of sound in dry air is 331.4. What is the percent error?
0.51%
Explain the effect of changing the launch angle on: time of flight, maximum height and range. At what launch angle, the range is maximum.
A higher launch angle results in a longer flight time, higher maximum height and a longer range. The steeper angle has a larger vertical velocity component which causes the object to fly higher, travel farther and stay in the air longer.
analysis and results
Answers to Analysis Questions Sample calculations, showing the steps clearly. Result Tables contain the headers and units. These tables need to be explained in the report. * Result Graphs will contain axis titles, units, scale, labels, and etc. These graphs need to be explained in the report. ** Answers to Post Lab Questions
As you moved the satellite to a greater distance from Earth, you adjusted the velocity to keep the circular orbit. As distance increases; new adjusted velocity increases? decrease? or stays same?
As the distance increased, I adjusted the velocity vector by decreasing the magnitude.
How does acceleration change as force increases? Choose one: increase, decrease, stay same.
As the force increases, the acceleration increases due to the fact that force is directly proportional to acceleration.
How does gravitational force change as the planet mass increase? Choose one: increase, decrease or stay same.
As the mass of the planet increases, the gravitational force also increases.
As you increase the orbital radius, how does the period change? Choose one: increase, decrease or stay same.
As the orbital radius increased, the period also increased.
Cover Page will include
Author Student Name(s), Lab Group Members, Course name and number, Title and date of the experiment
Inspect the momentum ratios in Table 2. Is momentum conserved in your collisions?
Based on table 2, the momentum is conserved because the values before and after the collision are the same. Also, the ratio is one which further proves that the momentum was unchanged
An "Analysis" section in the lab report contains
Calculations
Inspect kinetic energy ratios in Table 3. Is kinetic energy conserved in Part I? How about Part II and Part III?
During part one, the kinetic energy was conserved because the elasticity was turned to 100% and an elastic collision occurred. In part two and three, the kinetic energy is not conserved because some energy was lost during the collision and they were not considered elastic collisions.
If the total kinetic energy for a system is the same before and after the collision, we say that kinetic energy is conserved. If kinetic were conserved, what would be the ratio of the total kinetic energy after the collision to the total kinetic energy before the collision?
If the kinetic energy was conserved, the ratio of total kinetic energies would be one. This is only true for elastic conditions, whereas in inelastic and completely inelastic collisions the ratio would be different. For example, runs 3-6 have a distinct ratio due to energy loss throughout the collision.
If the total momentum for a system is the same before and after the collision, we say that momentum is conserved. If momentum were conserved, what would be the ratio of the total momentum after the collision to the total momentum before the collision?
If the momentum was conserved, the ratio of the total momentum after the collision to the total momentum before the collision would be equal to one. The values would be the same, resulting in a ratio of one.
objective of lab 6- conservation of energy
In this experiment, you are investigating the relationship between kinetic energy, potential energy, and total energy when only conservative forces are present.
objective of lab 7- momentum, energy, and collisions
In this experiment, you will observe different types of collisions between two balls and test for the conservation of momentum and conservation of energy. Based on the energy changes, you will classify collisions as elastic, inelastic, or completely inelastic.
lab 1 objective vector addition
In this lab, students will practice graphical and analytical vector addition.
objective of lab 8- torque and equilibrium
In this lab, you will explore the equilibrium conditions by balancing the plank.
objective of lab 9- simple pendulum
In this lab, you will explore the periodic motion of a simple pendulum and the mathematical relationships to determine the experimental value for earth's gravitational acceleration.
How does gravitational force change as the satellite mass increase? Choose one: increase, decrease or stay same
It does not matter which object is increased, so increasing the satellite mass will also increase the gravitational force.
How is a playground swing like a pendulum?
Its motion is periodic; meaning, the swing's motion is repeated in equal intervals of time.
In an Atwood's machine experiment, students are asked to draw the velocity versus time graph of the moving mass on their lab notebook. Which is the NOT required element in the graph?
Legend
Refrences
List of the sources used to conduct the experiment, to analyze the data and to write the report
A "Purpose" section in the lab report contains
Objectives of the experiment
introduction
Objectives: Purpose of the experiment Theory: A brief explanation of the physics concepts studied and the list of the equations used. Should not exceed a page. Materials: List of the equipment used Procedure: Summary of the procedures followed by students. Wording should not be copied from lab instructions, needs to be original. Should not exceed a page.
Classify the three collision types (Part I, Part II, Part III) as elastic, inelastic, or completely inelastic. Briefly explain your reasoning.
Part one was an elastic collision because the total kinetic energy of the two balls remained the same. There was no energy conversion between kinetic energy and another form of energy, such as heat or potential energy. In contrast, part two was an inelastic collision because the kinetic energy was not conserved. This could have been due to an external force acting upon the balls. Lastly, part three was a completely inelastic collision because most of the kinetic energy was lost. The balls also stuck together after the collision, which is another indication of a perfectly inelastic collision.
Kim is writing physics lab report for the "Force Table" experiment. After reviewing her report, she noticed that there is some unnecessary information. Some of the section headings of Kim's report are listed below. Indicate the section, which she could eliminate from her report.
Prediction
What is the purpose of physics lab logbook/notebook ?
Record any information during the lab
objective of lab 4- newtons laws
Study Newton's Laws of Motion.
Students have conducted the Behavior of a Gas experiment in a physics lab. The equipment is pressure sensor, syringe and data collection device (LabQuest). At first, they placed the syringe at 5 mL and then connected to the pressure sensor. As they varied the volume, they recorded the pressure and the volume in the syringe. They have plotted the data. The pressure vs volume graph is shown on the right. What is the purpose of this experiment?
Study the pressure dependence on volume
Kim is writing physics lab report for the "Force Table" experiment. After reviewing the conclusion section, she noticed that there is some unnecessary information. Indicate the information, which she could eliminate from the conclusion
Summary of the Procedure
discussion and conclusion
Summary of the findings and result. Discussion on how good the results compared to the objectives of the experiment. Comparison of the results with accepted values. Discussion on the sources of the errors. Discussion on the areas of improvement. Other comments
Does your system obey the 1st condition of static equilibrium? Explain.
The 1st condition of static equilibrium states that the net external forces must equal zero. This is true because both x and y components have a net force of zero.
Does your system obey the 2nd condition of static equilibrium? Explain
The 2nd condition of static equilibrium states that the net torque must equal zero. This is proven to be true based on the last calculation.
Compare the Gravitational Potential Energy for all runs. Explain the pattern.
The Gravitational Potential Energy decreases as the height decreases. As the man travels down the ramp, his potential energy is converted into kinetic energy due to his increased speed. Gravity is pulling the skater towards the earth, causing his height to decrease and his speed to increase.
Compare the speed and Kinetic Energy for all runs. Explain the pattern
The Kinetic Energy is directly related to the skater's speed. The faster he goes, the higher his Kinetic Energy is. More specifically, the skater increases his kinetic energy as the speed is squared.
How does the gravitational force change as the distance between Earth and satellite increase? Choose one: increase, decrease or stay same.
The gravitational force decreases as the distance between the earth and the satellite increases.
What is the direction of the gravitational force acting on the satellite during the circular motion around Earth?
The gravitational force is directed towards the center of the earth at every point during the circular motion.
Discuss the effect of changing mass on the speed of the skater as moves down the ramp? Compare the speed of the skater at the bottom of the ramp for different masses. How does mass affect PE, KE and E?
The mass of the skater effects the acceleration, but not his speed. However, the amount of kinetic and potential energy changes with respect to mass. As the mass increases, the potential and kinetic energy also increases. The mathematical formulas also prove this to be true because mass has a linear relationship with energy. By increasing the kinetic and potential energy, the total mechanical energy will automatically increase. This does not disprove the fact that energy is neither created nor destroyed, it will just alter the amount of total energy transferred and conserved.
What produces this repetitive motion?
The motion of both a swing and a pendulum is the product of a variable force acting on them, called a linear restoring force.
From such a graphical representation, many characteristics of an object's motion can be obtained such as:
The objects speed (v) The direction the object is traveling (+v; −v) The acceleration at which the object is traveling (a) Whether the object is speeding up (velocity and acceleration point in same direction), or slowing down (velocity and acceleration point in opposite direction). How far the object has traveled (Δx)
Is total mechanical energy conserved in the experiment as skater moves down on the ramp when there is friction on the ramp? Explain
The potential and kinetic energy is being transferred to thermal energy which in turn releases a net amount of energy. The total energy of the universe would be conserved but not necessarily the energy of the skater. The energy is being lost due to friction but is not being destroyed.
Explain the effect of changing the projectile type on: time of flight, maximum height and range
The projectile type does not influence the time, the maximum height, or the range. This is because only the vertical component, which is gravity, is affecting the object. The horizontal velocity is the same for each object and it stays constant the entire time.
lab 2 objective- motion graphs
The purpose of this experiment is for you to correctly understand the relationships between position, velocity, and acceleration with time.
objective of lab 5- circular motion
The purpose of this experiment is to study the gravitation and circular motion of satellites.
lab 3 objective- projectile motion
The purpose of this experiment is to study two-dimensional motion. Kinematics equations for the projectile motion, with zero launch angle, are practiced.
Explain the meaning of the slope in a position vs. time graph. What motion is occurring when there is a positive slope? What motion is occurring with a negative slope? What motion is occurring with a zero slope?
The slope of a position vs. time graph represents the velocity. When there is a positive slope the velocity is also positive and the object, in this case the man, is moving in a positive direction. When there is a negative slope, the man is moving in the opposite direction which represents the negative direction. Lastly, when the slope is zero that means the velocity is at zero and the man is at rest.
Explain the meaning of the slope in a velocity vs. time graph. Describe the motion of an object if the slope of a velocity vs. time graph is zero. Describe the motion of an object if the slope of a velocity vs. time graph is not zero.
The slope of a velocity vs. time graph represents the objects acceleration. If the slope is zero, the object is not accelerating, which also shows that the object is moving with a constant velocity. When the slope is not zero, that means that the object is speeding up or slowing down. For example, when the slope is positive and steep, the object is speeding up and increasing its velocity. This is the same concept for a negative slope but reverse.
Discuss the effect of friction on the speed of the skater as moves down the ramp? Compare the speed of the skater at the bottom of the ramp when there is no friction and there is some friction.
The speed of the skater decreases when friction is added. This is because friction is an external force which causes resistance. Without friction, the bottom of the ramp is the fastest point on the ramp, but when there is friction present the lowest point on the ramp is the slowest. The skater will eventually stop at the very bottom and he will have a speed of 0 m/s because of the friction.
As object at rest, how the static fraction force changes as the applied force increased? Choose one: increase, decrease, stay same.
The static friction force increases when the applied force increases. The static friction force will apply an equal but opposite force in order to keep the object at rest.
Is total mechanical energy conserved in the experiment as skater moves down on the ramp in Part I? Explain
The total mechanical energy is conserved in the experiment because there are no external forces changing the total energy. The forces present are doing positive work and the energy is just being transferred between potential energy and kinetic energy.
Compare the total mechanical energy of all runs
The total mechanical energy stays around the same value for all runs. There are no external forces doing work on the skater, so there is no change in the total mechanical energy.
How does velocity change as the distance between Earth and satellite increase? Choose one: increase, decrease or stay same.
The velocity decreases as the distance between the earth and satellite increase. Distance is inversely related to velocity.
What is the direction of the satellite velocity during the circular motion around Earth
The velocity of the satellite is directed tangent to the circular path around the earth.
Explain how velocity vector change during the flight: x-component, y-component, and total
The velocity vector for the x-component is constant throughout the entire flight, while the y component is changing by 9.80 m/s each second. The total velocity vector depends on the x and y components. Since the x-component is constant and the y-component is increasing by 9.80 m/s every second, the total vector will also increase on the way down.
Explain how acceleration vector change during the flight: x-component, y-component, and total
The x- component does not have an acceleration while the y-component has a constant acceleration throughout the flight. This is due to the fact that gravity is the only force effecting acceleration. The total acceleration vector is just the y-component because gravity is only along the y-axis.
data
This section will include all the data taken in the lab. Data Tables will contain the headers and units. * Data Graphs will contain axis titles, units, scale, labels, and etc. **
In physics lab, students are asked to design an experiment to study the Conservation of Energy. Which of the following data gathered in the experiment can be used for this purpose?
Using a projectile launcher, shoot the ball upward. Measure and determine the initial and final velocities and vertical positions.
Explain the effect of air resistance on: time of flight, maximum height and range. The effect is better observed with baseball
When air resistance is present, the objects trajectory changes. The time of flight, the maximum height, and the range are all reduced.
As object moving, how the kinetic fraction force changes as the applied force increased? Choose one: increase, decrease, stay same.
When an object is moving, the kinetic friction force will remain the same regardless of the applied force.
How does satellite path change when gravity is turned off?
When gravity is turned off, the satellite will travel in a straight line.
Explain the effect of changing the initial height on: time of flight, maximum height, range
When the initial height is increased, the time in the air, the maximum height, and the horizontal range also increases. Starting at a lower height causes the object to reach the ground faster, resulting in a faster air time, lower maximum height and a shorter range.
Explain the effect of changing the initial speed on: time of flight (t), maximum height (y) and range (x).
When the initial speed is increased, the time, the maximum height and the range also increases. The opposite is true when the initial speed decreases. The time it takes to hit the ground, the maximum height, and the range reduces as the speed decreases.
How does acceleration change as mass increases? Choose one: increase, decrease, stay same
When the mass of an object increases, the acceleration decreases because there is an inverse relationship between acceleration and mass
How does the velocity change when the net force equals to zero? What about when net force has a nonzero value?
When the net force changes to equal zero, the velocity stops changing and stays at a constant velocity the rest of the time. When the net force is a nonzero value, the velocity keeps increases.
The coefficient of friction
a constant used in determining the friction between the two surfaces.
Friction force
acts on objects due to the intermolecular interactions between two surfaces. The friction force is smaller for smooth surfaces and larger in rough surfaces.
Since only the direction and not the magnitude of the velocity changes, the acceleration must
be directed perpendicular to the velocity, resulting acceleration in the radial direction.
Once the bob passes through the equilibrium position its velocity begins to
decrease as it moves up and away, until it stops at the peak of its swing. At this point the bob begins to fall back towards the equilibrium position again subject to the same restoring force, and the changing velocity cycle starts over.
Collisions are classified as
elastic (kinetic energy is conserved), inelastic (kinetic energy is lost) or completely inelastic (the objects stick together after collision).
There are three different methods of vector addition:
experimental, analytical, and graphical.
The vertical component of acceleration is equal to
gravitational acceleration
According to the Newton's Laws of Universal Gravitation, any particle
in universe applies an attractive force on each other.
For a pendulum, the velocity of the bob
increases as it approaches the equilibrium position until it reaches the equilibrium position where it achieves maximum velocity
The free-body diagram
is a graphical tool to visualize the forces acting on the object and sum them using the vector addition methods.
The projectile motion
is the two dimensional motion of an object under the influence of gravity
A rigid body is in equilibrium if
it has zero translational acceleration and zero angular acceleration.
fk = μsFN:
kinetic frictional force
fs = μsFN :
maximum static force, just before slipping
The collision of two balls on a track can be described in terms of
momentum conservation and, in some cases, energy conservation.
fs ≤ μsFN :
static frictional force, increases to match external force
The Newton's 1st Law states
that the object keeps its state of motion, stays at rest or moves at constant velocity, unless a net force acting on it.
The Newton's 3rd Law
that when one objects applies a force on the second object, then second object applies a reaction force on the first object with same magnitude, but opposite direction
The Newton's 2nd Law
the mathematical relationship between force, acceleration and mass ∑𝐹⃗ = 𝑚a
For the swing, the equilibrium position is
the point at which the force from gravity is counteracted completely by the tension from the swing's chains. This is where the swing hangs motionless below its point of anchor.
The equilibrium position for a pendulum is defined as
the point at which the net force (and torque) acting on the pendulum "bob" is zero
When a swing or pendulum is displaced from its equilibrium position
the restoring force begins to act on the swing inducing motion back towards the equilibrium position.
The total mechanical energy of an object is
the sum of its gravitational potential energy and its kinetic energy.
In equilibrium,
the sum of the externally applied forces is zero, and the sum of the externally applied torques is zero.
Although the speed of the object is constant, the direction of motion is continuously changing; thus,
the velocity is continuously changing and the object experiences a net acceleration.
In the absence of friction,
total mechanical energy is conserved; initial mechanical energy equals to the final mechanical energy
When an object moves with constant speed in a circular path, it is said to move with
uniform circular motion
If there is no net external force experienced by the system of two balls, then
we expect the total momentum of the system to be conserved. This is true regardless of the force acting between the balls.
In the case where an object is in motion,
we specify that the coefficient of friction is kinetic, μk.
When objects are at rest,
we specify that the coefficient of friction is static, μs
In projectile motion, the horizontal component of the acceleration is
zero
𝑅𝑥 = 𝑅𝑦 =
𝐴𝑥 + 𝐵𝑥 𝐴𝑦 + 𝐵y
the x and y components of a vector can be calculated as
𝐴𝑥 = 𝐴 cos 𝜃 and 𝐴𝑦 = 𝐴 sin 𝜃
The magnitude and direction of 𝑅⃗⃗ can then be found as
𝑅 = √𝑅𝑥 ^2+ 𝑅𝑦 ^2 θ = tan−1 𝑅𝑦/ 𝑅x
Kepler's 3rd Law
𝑇 = 2𝜋𝑟 3/2 √𝐺𝑀e This equation describes the relationship between period and orbital radius of a satellite
