AP Physics 1 Flashcards: Conservation Of Energy

What this deck covers

This deck focuses on Conservation Of Energy, giving you a quick way to review the definitions, rules, and examples that matter most for AP Physics 1.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: State the formula for work done by a force.

Answer: $W = F \times d \times \text{cos}(\theta)$. Work depends on force, displacement, and angle between them.

Flashcard 2: What is the unit of energy in the International System?

Answer: Joule. Standard SI unit for all forms of energy and work.

Flashcard 3: Calculate total energy if a 5 kg object at 10 m has 200 J KE.

Answer: Total Energy = 690 J. Using $PE = mgh = (5)(9.8)(10) = 490$ J, total = $200 + 490 = 690$ J.

Flashcard 4: Calculate the work done by a 20 N force over 3 m at 0°.

Answer: $W = 60 \text{ J}$. Using $W = Fd\cos(0°) = (20)(3)(1) = 60$ J.

Flashcard 5: Identify the energy transformation in a pendulum.

Answer: Potential to kinetic and vice versa. Pendulum continuously exchanges kinetic and potential energy.

Flashcard 6: What is the energy form of a charged battery?

Answer: Chemical potential energy. Energy stored in chemical bonds for later use.

Flashcard 7: Identify an example of a non-conservative force.

Answer: Friction. Always opposes motion and converts mechanical energy to heat.

Flashcard 8: What is the energy form of a charged battery?

Answer: Chemical potential energy. Energy stored in chemical bonds for later use.

Flashcard 9: Identify the primary energy conversion in solar panels.

Answer: Light to electrical energy. Photovoltaic cells convert sunlight into electrical energy.

Flashcard 10: Identify the energy transformation in a pendulum.

Answer: Potential to kinetic and vice versa. Pendulum continuously exchanges kinetic and potential energy.

Flashcard 11: Calculate power if 60 J is used in 3 seconds.

Answer: Power = 20 W. Using $P = \frac{W}{t} = \frac{60}{3} = 20$ W.

Flashcard 12: Which energy transformation occurs when a ball is thrown upwards?

Answer: Kinetic to potential energy. Ball slows down as it gains height, converting motion to position energy.

Flashcard 13: Calculate the elastic potential energy for $k = 200 \text{ N/m}$ and $x = 0.1 \text{ m}$.

Answer: $PE = 1 \text{ J}$. Using $PE = \frac{1}{2}kx^2 = \frac{1}{2}(200)(0.1^2) = 1$ J.

Flashcard 14: What is the energy transformation in a generator?

Answer: Mechanical to electrical energy. Converts rotational motion into electrical energy output.

Flashcard 15: State the energy conservation principle.

Answer: Energy cannot be created or destroyed. First law of thermodynamics: energy is conserved in all processes.

Flashcard 16: Find the total mechanical energy if KE = 50 J and PE = 30 J.

Answer: Total Energy = 80 J. Mechanical energy is the sum of kinetic and potential energies.

Flashcard 17: What is the energy transformation in a generator?

Answer: Mechanical to electrical energy. Converts rotational motion into electrical energy output.

Flashcard 18: Identify the type of force that conserves mechanical energy.

Answer: Conservative force. Forces like gravity where work is path-independent.

Flashcard 19: Find the power if 300 J is used in 10 seconds.

Answer: Power = 30 W. Using $P = \frac{W}{t} = \frac{300}{10} = 30$ W.

Flashcard 20: Which energy transformation occurs when a ball is thrown upwards?

Answer: Kinetic to potential energy. Ball slows down as it gains height, converting motion to position energy.

Flashcard 21: What is the energy conversion in a hydroelectric dam?

Answer: Potential to kinetic to electrical energy. Water falls, spins turbines, generates electricity.

Flashcard 22: Define power in terms of energy.

Answer: Power is the rate of energy transfer. How quickly energy is transferred or transformed.

Flashcard 23: What is the potential energy formula for a spring?

Answer: $PE = \frac{1}{2}kx^2$. Energy stored in compressed or stretched springs.

Flashcard 24: Find the kinetic energy of a 3 kg object moving at 4 m/s.

Answer: $KE = 24 \text{ J}$. Using $KE = \frac{1}{2}mv^2 = \frac{1}{2}(3)(4^2) = 24$ J.

Flashcard 25: Find the gravitational potential energy of a 5 kg object 10 m high.

Answer: $PE = 490 \text{ J}$. Using $PE = mgh = (5)(9.8)(10) = 490$ J.

Flashcard 26: State what happens to energy in inelastic collisions.

Answer: Mechanical energy is not conserved. Some kinetic energy converts to heat and sound.

Flashcard 27: Find the mechanical energy if a system has 100 J of KE and 200 J of PE.

Answer: Mechanical Energy = 300 J. Sum of kinetic and potential energies in the system.

Flashcard 28: Calculate potential energy of a 2 kg object at height 6 m.

Answer: $PE = 117.6 \text{ J}$. Using $PE = mgh = (2)(9.8)(6) = 117.6$ J.

Flashcard 29: Find the mechanical energy if a system has 100 J of KE and 200 J of PE.

Answer: Mechanical Energy = 300 J. Sum of kinetic and potential energies in the system.

Flashcard 30: Define the Conservation of Mechanical Energy.

Answer: Total mechanical energy is constant if only conservative forces act. When only gravity and springs act, $KE + PE$ stays constant.

Flashcard 31: What is the energy form of light emitted by a bulb?

Answer: Radiant energy. Electromagnetic energy in the form of visible light waves.

Flashcard 32: Calculate total energy if a 5 kg object at 10 m has 200 J KE.

Answer: Total Energy = 690 J. Using $PE = mgh = (5)(9.8)(10) = 490$ J, total = $200 + 490 = 690$ J.

Flashcard 33: Identify the energy form of a moving car.

Answer: Kinetic energy. Energy due to motion of the vehicle.

Flashcard 34: Find the gravitational potential energy of a 5 kg object 10 m high.

Answer: $PE = 490 \text{ J}$. Using $PE = mgh = (5)(9.8)(10) = 490$ J.

Flashcard 35: Calculate power if 60 J is used in 3 seconds.

Answer: Power = 20 W. Using $P = \frac{W}{t} = \frac{60}{3} = 20$ W.

Flashcard 36: Identify the type of force that conserves mechanical energy.

Answer: Conservative force. Forces like gravity where work is path-independent.

Flashcard 37: What does it mean for a force to be non-conservative?

Answer: Energy is not conserved; work depends on path. Work depends on path taken; mechanical energy decreases.

Flashcard 38: What happens to total energy in an isolated system?

Answer: It remains constant. Energy can only be transformed, never created or destroyed.

Flashcard 39: Find the total mechanical energy if KE = 50 J and PE = 30 J.

Answer: Total Energy = 80 J. Mechanical energy is the sum of kinetic and potential energies.

Flashcard 40: What is the relationship between work and energy?

Answer: Work is a transfer of energy. Work transfers energy from one system to another.

Flashcard 41: Calculate the elastic potential energy for $k = 200 \text{ N/m}$ and $x = 0.1 \text{ m}$.

Answer: $PE = 1 \text{ J}$. Using $PE = \frac{1}{2}kx^2 = \frac{1}{2}(200)(0.1^2) = 1$ J.

Flashcard 42: What is the unit of energy in the International System?

Answer: Joule. Standard SI unit for all forms of energy and work.

Flashcard 43: What is the formula for power in terms of work?

Answer: $P = \frac{W}{t}$. Power equals work done divided by time taken.

Flashcard 44: Find the increase in KE if work done is 150 J.

Answer: Increase in KE = 150 J. Work-energy theorem: work done equals change in kinetic energy.

Flashcard 45: What is the unit of power in the International System?

Answer: Watt. Standard SI unit for power (energy per unit time).

Flashcard 46: Calculate potential energy of a 2 kg object at height 6 m.

Answer: $PE = 117.6 \text{ J}$. Using $PE = mgh = (2)(9.8)(6) = 117.6$ J.

Flashcard 47: Calculate the work done by a 20 N force over 3 m at 0°.

Answer: $W = 60 \text{ J}$. Using $W = Fd\cos(0°) = (20)(3)(1) = 60$ J.

Flashcard 48: What is the energy form of a wound-up clock spring?

Answer: Elastic potential energy. Energy stored by winding the spring mechanism.

Flashcard 49: What is the potential energy formula for a spring?

Answer: $PE = \frac{1}{2}kx^2$. Energy stored in compressed or stretched springs.

Flashcard 50: What happens to total energy in an isolated system?

Answer: It remains constant. Energy can only be transformed, never created or destroyed.

Flashcard 51: Identify the energy form of a compressed spring.

Answer: Elastic potential energy. Energy stored when spring is compressed or stretched.

Flashcard 52: What is the energy form of a wound-up clock spring?

Answer: Elastic potential energy. Energy stored by winding the spring mechanism.

Flashcard 53: Calculate work if a 50 N force moves an object 4 m at 60°.

Answer: $W = 100 \text{ J}$. Using $W = Fd\cos(60°) = (50)(4)(0.5) = 100$ J.

Flashcard 54: Find and correct the error: 'Energy is lost in a closed system.'

Answer: Correct: 'Energy is transformed, not lost.'. Energy is conserved in closed systems, only transformed.

Flashcard 55: State what happens to energy in inelastic collisions.

Answer: Mechanical energy is not conserved. Some kinetic energy converts to heat and sound.

Flashcard 56: What is the formula for kinetic energy?

Answer: $KE = \frac{1}{2}mv^2$. Energy of motion depends on mass and velocity squared.

Flashcard 57: Find the power if 300 J is used in 10 seconds.

Answer: Power = 30 W. Using $P = \frac{W}{t} = \frac{300}{10} = 30$ W.

Flashcard 58: What is the formula for gravitational potential energy?

Answer: $PE = mgh$. Energy due to position in gravitational field.

Flashcard 59: Define power in terms of energy.

Answer: Power is the rate of energy transfer. How quickly energy is transferred or transformed.