4 min read•november 29, 2021
👋 Welcome to the AP Physics Unit 4 FRQ (Energy) Answers. Have your responses handy as you go through the rubrics to see how you did!
⏱ Remember, the AP Physics 1 exam has 5 free-response questions, and you will be given 90 minutes to complete the FRQ section. (This means you should give yourself ~18 minutes to go through each practice FRQ.)
A projectile launcher consists of a spring with an attached plate, as shown in Figure 1. When the spring is compressed, the plate can be held in place by a pin at any of five positions A, B, C, D, or E.
For example, Figure 2 shows a ball placed against the plate, which is held in place by a pin at position A. The ball is launched upon release of the pin.
A student hypothesizes that the spring constant can be determined by launching the ball using different compression distances.
📄 Additional Resources
Study Guide: Conservation of Energy, the Work-Energy Principle, and Power
Design an experimental procedure to test the hypothesis in which the student uses the launcher to launch the ball. Assume equipment usually found in a school physics laboratory is available.
Quantity to be Measured | Symbol for Quantity | Equipment for Measurement |
mass | kg | balance |
compression | x | ruler |
speed | V | photogate |
height | ∆y | meterstick |
1pt = Diagram
1pt = SQuA (Measurement 1 & equipment)
1pt = SQuA (Measurement 2 & equipment)
1pt = Repeated Variable (Change the compression)
1pt = Error Reduction (Do 3 trials for each pin, then average the compression values)
The student completes the experiment and obtains the data below. Using the data that most closely matches your experimental procedure, determine the spring constant for the spring.
Mass of Tennis Ball: 0.056 kg
Pin Location | Compression (m) | Maximum Height of Ball After Launch (m) | Maximum Launch Speed of Ball Exiting Launcher (m/s) | 2mgh | mv^2 | x^2 |
A | 0.1 | 0.31 | 2.45 | 0.35 | 0.34 | 0.01 |
B | 0.2 | 1.22 | 4.90 | 1.37 | 1.34 | 0.04 |
C | 0.3 | 2.76 | 7.35 | 3.09 | 3.03 | 0.09 |
D | 0.4 | 4.90 | 9.80 | 5.49 | 5.38 | 0.16 |
E | 0.5 | 7.65 | 12.2 | 8.57 | 8.34 | 0.25 |
📄 Additional Resources
Study Guide: Energy
🧠 Want to continue reinforcing your knowledge of Unit 4? Check out Unit 4 Trivia, either as a document or as a game.
⏭ Ready to move on to the next topic? Take a look at the collection of Unit 5 Resources.
📚 Want to review multiple units? Check out all of the AP Physics 1 FRQs.
Balance
: Balance refers to an object's ability to stay stable and not tip over. It involves distributing weight evenly so that forces acting on it do not cause it to fall or lean excessively in one direction.Compression
: Compression refers to applying pressure or squeezing something together, resulting in a decrease in volume or size.Conservation of Energy
: The principle that states that energy cannot be created or destroyed but can only be transferred or transformed from one form to another.experimental uncertainty
: Experimental uncertainty refers to the inherent limitations and errors associated with measurements and observations made during scientific experiments. It accounts for variations, inaccuracies, and unknown factors affecting data reliability.Height
: Height refers to the vertical distance above a reference point or surface. It is commonly used to describe how tall something is.Mass
: Mass refers to the amount of matter an object contains. It is a measure of the inertia or resistance to changes in motion.Meterstick
: A meterstick is a measuring tool that is one meter long and is used to measure length or distance.Photogate
: A photogate is an electronic sensor that uses light beams to detect objects passing through it and measures their speed or time.Power
: Power is the rate at which work is done or energy is transferred. It measures how quickly work is being done.Ruler
: A ruler is a straight, flat tool used to measure the length or distance between two points.Speed
: The rate at which an object moves or changes position over time.Spring Constant
: The spring constant represents how stiff or flexible a spring is. It determines how much force will be required to stretch or compress a spring by a certain distance.Work-Energy Principle
: The work-energy principle states that the work done on an object equals its change in kinetic energy. It relates the concept of work, which is the transfer of energy through force, to changes in an object's motion and energy.4 min read•november 29, 2021
👋 Welcome to the AP Physics Unit 4 FRQ (Energy) Answers. Have your responses handy as you go through the rubrics to see how you did!
⏱ Remember, the AP Physics 1 exam has 5 free-response questions, and you will be given 90 minutes to complete the FRQ section. (This means you should give yourself ~18 minutes to go through each practice FRQ.)
A projectile launcher consists of a spring with an attached plate, as shown in Figure 1. When the spring is compressed, the plate can be held in place by a pin at any of five positions A, B, C, D, or E.
For example, Figure 2 shows a ball placed against the plate, which is held in place by a pin at position A. The ball is launched upon release of the pin.
A student hypothesizes that the spring constant can be determined by launching the ball using different compression distances.
📄 Additional Resources
Study Guide: Conservation of Energy, the Work-Energy Principle, and Power
Design an experimental procedure to test the hypothesis in which the student uses the launcher to launch the ball. Assume equipment usually found in a school physics laboratory is available.
Quantity to be Measured | Symbol for Quantity | Equipment for Measurement |
mass | kg | balance |
compression | x | ruler |
speed | V | photogate |
height | ∆y | meterstick |
1pt = Diagram
1pt = SQuA (Measurement 1 & equipment)
1pt = SQuA (Measurement 2 & equipment)
1pt = Repeated Variable (Change the compression)
1pt = Error Reduction (Do 3 trials for each pin, then average the compression values)
The student completes the experiment and obtains the data below. Using the data that most closely matches your experimental procedure, determine the spring constant for the spring.
Mass of Tennis Ball: 0.056 kg
Pin Location | Compression (m) | Maximum Height of Ball After Launch (m) | Maximum Launch Speed of Ball Exiting Launcher (m/s) | 2mgh | mv^2 | x^2 |
A | 0.1 | 0.31 | 2.45 | 0.35 | 0.34 | 0.01 |
B | 0.2 | 1.22 | 4.90 | 1.37 | 1.34 | 0.04 |
C | 0.3 | 2.76 | 7.35 | 3.09 | 3.03 | 0.09 |
D | 0.4 | 4.90 | 9.80 | 5.49 | 5.38 | 0.16 |
E | 0.5 | 7.65 | 12.2 | 8.57 | 8.34 | 0.25 |
📄 Additional Resources
Study Guide: Energy
🧠 Want to continue reinforcing your knowledge of Unit 4? Check out Unit 4 Trivia, either as a document or as a game.
⏭ Ready to move on to the next topic? Take a look at the collection of Unit 5 Resources.
📚 Want to review multiple units? Check out all of the AP Physics 1 FRQs.
Balance
: Balance refers to an object's ability to stay stable and not tip over. It involves distributing weight evenly so that forces acting on it do not cause it to fall or lean excessively in one direction.Compression
: Compression refers to applying pressure or squeezing something together, resulting in a decrease in volume or size.Conservation of Energy
: The principle that states that energy cannot be created or destroyed but can only be transferred or transformed from one form to another.experimental uncertainty
: Experimental uncertainty refers to the inherent limitations and errors associated with measurements and observations made during scientific experiments. It accounts for variations, inaccuracies, and unknown factors affecting data reliability.Height
: Height refers to the vertical distance above a reference point or surface. It is commonly used to describe how tall something is.Mass
: Mass refers to the amount of matter an object contains. It is a measure of the inertia or resistance to changes in motion.Meterstick
: A meterstick is a measuring tool that is one meter long and is used to measure length or distance.Photogate
: A photogate is an electronic sensor that uses light beams to detect objects passing through it and measures their speed or time.Power
: Power is the rate at which work is done or energy is transferred. It measures how quickly work is being done.Ruler
: A ruler is a straight, flat tool used to measure the length or distance between two points.Speed
: The rate at which an object moves or changes position over time.Spring Constant
: The spring constant represents how stiff or flexible a spring is. It determines how much force will be required to stretch or compress a spring by a certain distance.Work-Energy Principle
: The work-energy principle states that the work done on an object equals its change in kinetic energy. It relates the concept of work, which is the transfer of energy through force, to changes in an object's motion and energy.© 2024 Fiveable Inc. All rights reserved.
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