AP Physics 1 Flashcards: Forces And Free Body Diagrams

What this deck covers

This deck focuses on Forces And Free Body Diagrams, 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: Identify the main force that acts at a distance without contact.

Answer: Gravitational force. Gravity acts between all masses without physical contact.

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

Answer: Newton (N). Named after Isaac Newton; equivalent to $\text{kg} \cdot \text{m/s}^2$.

Flashcard 3: Calculate the gravitational force on a 10 kg mass on Earth's surface.

Answer: $F = 98 \text{ N}$. Using $W = mg = 10 \times 9.8 = 98 \text{ N}$.

Flashcard 4: What is the unit of gravitational constant $G$?

Answer: $\text{N m}^2 \text{kg}^{-2}$. Units derived from $F = G \frac{m_1 m_2}{r^2}$ dimensional analysis.

Flashcard 5: What is the effect on acceleration if net force is doubled?

Answer: Acceleration doubles. From $F = ma$; doubling force doubles acceleration for constant mass.

Flashcard 6: Choose the correct formula for tension in a rope with mass $m$ accelerating upward.

Answer: $T = m(g + a)$. Tension must overcome weight plus provide upward acceleration force.

Flashcard 7: State Newton's First Law of Motion.

Answer: An object in motion stays in motion unless acted on by a net external force. Also called the law of inertia; objects resist changes in motion.

Flashcard 8: What is the effect on net force if two equal forces act in opposite directions?

Answer: Net force is 0 N. Equal and opposite forces cancel completely.

Flashcard 9: State the formula for Newton's Second Law of Motion.

Answer: $F = ma$. Force equals mass times acceleration; fundamental dynamics equation.

Flashcard 10: Calculate the net force on an object with 8 N right and 3 N left.

Answer: 5 N to the right. Net force: $8 \text{ N} - 3 \text{ N} = 5 \text{ N}$ rightward.

Flashcard 11: What is the unit of gravitational constant $G$?

Answer: $\text{N m}^2 \text{kg}^{-2}$. Units derived from $F = G \frac{m_1 m_2}{r^2}$ dimensional analysis.

Flashcard 12: What is the direction of the net force on an object moving in a circle?

Answer: Towards the center of the circle. Centripetal force always points toward the center of circular motion.

Flashcard 13: How does increasing mass affect gravitational force?

Answer: Gravitational force increases. Force is proportional to both masses in gravitational equation.

Flashcard 14: What is the formula for kinetic frictional force?

Answer: $f_k = \text{μ}_k N$. Kinetic friction equals coefficient times normal force.

Flashcard 15: Find the net force if an object has forces of 5 N and 3 N in opposite directions.

Answer: Net force is 2 N in the direction of the larger force. Subtract opposing forces: $5 \text{ N} - 3 \text{ N} = 2 \text{ N}$.

Flashcard 16: Identify the force that acts between two charged objects.

Answer: Electrostatic force. Coulomb force between charges; can be attractive or repulsive.

Flashcard 17: Which force is responsible for an object sliding down an inclined plane?

Answer: Component of gravitational force parallel to the plane. Component $mg \sin \theta$ acts parallel to inclined surface.

Flashcard 18: What is the resultant force of 10 N and 15 N acting in the same direction?

Answer: 25 N in the direction of both forces. Add forces in same direction: $10 \text{ N} + 15 \text{ N} = 25 \text{ N}$.

Flashcard 19: What happens to friction if the normal force is doubled?

Answer: Friction doubles. Friction is directly proportional to normal force.

Flashcard 20: Find the value of the normal force on an inclined plane.

Answer: $N = mg \, \cos \theta$. Normal force is weight component perpendicular to inclined plane.

Flashcard 21: Find the value of the normal force on an inclined plane.

Answer: $N = mg \, \cos \theta$. Normal force is weight component perpendicular to inclined plane.

Flashcard 22: Identify the force that opposes the relative motion of two surfaces.

Answer: Frictional force. Kinetic and static friction resist sliding between contact surfaces.

Flashcard 23: Which force always acts opposite to the direction of motion?

Answer: Frictional force. Friction always opposes relative motion between surfaces in contact.

Flashcard 24: What is the resultant force of 10 N and 15 N acting in the same direction?

Answer: 25 N in the direction of both forces. Add forces in same direction: $10 \text{ N} + 15 \text{ N} = 25 \text{ N}$.

Flashcard 25: What is the term for the force causing an object to move in a circle?

Answer: Centripetal force. The net inward force required for circular motion.

Flashcard 26: What is the formula for gravitational force between two masses?

Answer: $F = G \frac{m_1 m_2}{r^2}$. Newton's law of universal gravitation relates force to masses and distance squared.

Flashcard 27: Calculate the net force on an object with 8 N right and 3 N left.

Answer: 5 N to the right. Net force: $8 \text{ N} - 3 \text{ N} = 5 \text{ N}$ rightward.

Flashcard 28: State Newton's Third Law of Motion.

Answer: For every action, there is an equal and opposite reaction. Forces always occur in equal and opposite pairs between objects.

Flashcard 29: Which force is responsible for an object sliding down an inclined plane?

Answer: Component of gravitational force parallel to the plane. Component $mg \sin \theta$ acts parallel to inclined surface.

Flashcard 30: Calculate the friction force for $μ_k = 0.3$ and $N = 50 \text{ N}$.

Answer: $f_k = 15 \text{ N}$. Using $f_k = \text{μ}_k N = 0.3 \times 50 = 15 \text{ N}$.

Flashcard 31: Identify the force that opposes the relative motion of two surfaces.

Answer: Frictional force. Kinetic and static friction resist sliding between contact surfaces.

Flashcard 32: Which force always acts opposite to the direction of motion?

Answer: Frictional force. Friction always opposes relative motion between surfaces in contact.

Flashcard 33: State Newton's Third Law of Motion.

Answer: For every action, there is an equal and opposite reaction. Forces always occur in equal and opposite pairs between objects.

Flashcard 34: How does increasing mass affect gravitational force?

Answer: Gravitational force increases. Force is proportional to both masses in gravitational equation.

Flashcard 35: Which force acts on a satellite orbiting Earth?

Answer: Gravitational force. Earth's gravity provides centripetal force for orbital motion.

Flashcard 36: Which force acts on a hanging object in a stationary elevator?

Answer: Tension equal to weight. Tension balances weight when elevator moves at constant velocity.

Flashcard 37: Find the normal force on a 10 kg object on a flat surface.

Answer: $N = 98 \text{ N}$. Normal force equals weight on horizontal surface: $N = mg$.

Flashcard 38: What is the formula for gravitational force between two masses?

Answer: $F = G \frac{m_1 m_2}{r^2}$. Newton's law of universal gravitation relates force to masses and distance squared.

Flashcard 39: What is the effect on net force if two equal forces act in opposite directions?

Answer: Net force is 0 N. Equal and opposite forces cancel completely.

Flashcard 40: Identify the force exerted by a surface perpendicular to the object.

Answer: Normal force. Normal force acts perpendicular to contact surfaces, preventing penetration.

Flashcard 41: What is the formula for centripetal force?

Answer: $F_c = \frac{mv^2}{r}$. Force needed to maintain circular motion at constant speed.

Flashcard 42: Choose the correct formula for tension in a rope with mass $m$ accelerating upward.

Answer: $T = m(g + a)$. Tension must overcome weight plus provide upward acceleration force.

Flashcard 43: Identify the force that balances the weight of a stationary object on a table.

Answer: Normal force. Normal force provides upward support equal to object's weight.

Flashcard 44: Which force acts on a hanging object in a stationary elevator?

Answer: Tension equal to weight. Tension balances weight when elevator moves at constant velocity.

Flashcard 45: Determine the tension in a rope holding a 5 kg mass at rest.

Answer: $T = 49 \text{ N}$. At rest, tension equals weight: $T = mg = 5 \times 9.8 = 49 \text{ N}$.

Flashcard 46: What is the formula for centripetal force?

Answer: $F_c = \frac{mv^2}{r}$. Force needed to maintain circular motion at constant speed.

Flashcard 47: Identify the force that balances the weight of a stationary object on a table.

Answer: Normal force. Normal force provides upward support equal to object's weight.

Flashcard 48: State the formula for Newton's Second Law of Motion.

Answer: $F = ma$. Force equals mass times acceleration; fundamental dynamics equation.

Flashcard 49: What is the formula for calculating weight?

Answer: $W = mg$. Weight equals mass times gravitational acceleration ($g = 9.8 \text{ m/s}^2$).

Flashcard 50: What is the formula for static frictional force?

Answer: $f_s \, \leq \, \text{μ}_s N$. Static friction can vary up to maximum value $\text{μ}_s N$.

Flashcard 51: What is the formula for restoring force in a spring?

Answer: $F = -kx$. Hooke's law; negative sign indicates force opposes displacement.

Flashcard 52: What is the formula for static frictional force?

Answer: $f_s \, \leq \, \mu_s N$. Static friction can vary up to maximum value $\mu_s N$.

Flashcard 53: What is the direction of the net force on an object moving in a circle?

Answer: Towards the center of the circle. Centripetal force always points toward the center of circular motion.

Flashcard 54: Identify the main force that acts at a distance without contact.

Answer: Gravitational force. Gravity acts between all masses without physical contact.

Flashcard 55: What happens to friction if the normal force is doubled?

Answer: Friction doubles. Friction is directly proportional to normal force.

Flashcard 56: What is the formula for kinetic frictional force?

Answer: $f_k = \mu_k N$. Kinetic friction equals coefficient times normal force.

Flashcard 57: What is the effect on acceleration if net force is doubled?

Answer: Acceleration doubles. From $F = ma$; doubling force doubles acceleration for constant mass.

Flashcard 58: Determine the tension in a rope holding a 5 kg mass at rest.

Answer: $T = 49 \text{ N}$. At rest, tension equals weight: $T = mg = 5 \times 9.8 = 49 \text{ N}$.

Flashcard 59: Identify the net force on an object in equilibrium.

Answer: Net force is 0 N. In equilibrium, all forces cancel out, resulting in zero net force.

Flashcard 60: What is the unit of force in the International System of Units?

Answer: Newton (N). Named after Isaac Newton; equivalent to $\text{kg} \cdot \text{m/s}^2$.

Flashcard 61: What is the formula for net force on an inclined plane?

Answer: $F_{\text{net}} = mg \, \sin \theta - f$. Gravity component minus friction determines net acceleration down plane.

Flashcard 62: Calculate the friction force for $μ_k = 0.3$ and $N = 50 \text{ N}$.

Answer: $f_k = 15 \text{ N}$. Using $f_k = \mu_k N = 0.3 \times 50 = 15 \text{ N}$.

Flashcard 63: Identify the force exerted by a surface perpendicular to the object.

Answer: Normal force. Normal force acts perpendicular to contact surfaces, preventing penetration.

Flashcard 64: What is the formula for net force on an inclined plane?

Answer: $F_{\text{net}} = mg \, \sin \theta - f$. Gravity component minus friction determines net acceleration down plane.

Flashcard 65: What is the relationship between acceleration and net force?

Answer: Directly proportional. From Newton's second law: $a = \frac{F}{m}$.

Flashcard 66: State the relationship between mass and weight.

Answer: Weight is mass times gravitational acceleration. Mass is intrinsic; weight depends on gravitational field strength.

Flashcard 67: State the relationship between mass and weight.

Answer: Weight is mass times gravitational acceleration. Mass is intrinsic; weight depends on gravitational field strength.

Flashcard 68: Find the normal force on a 10 kg object on a flat surface.

Answer: $N = 98 \text{ N}$. Normal force equals weight on horizontal surface: $N = mg$.

Flashcard 69: What is the term for the force causing an object to move in a circle?

Answer: Centripetal force. The net inward force required for circular motion.

Flashcard 70: Which force acts on a satellite orbiting Earth?

Answer: Gravitational force. Earth's gravity provides centripetal force for orbital motion.

Flashcard 71: What is the formula for restoring force in a spring?

Answer: $F = -kx$. Hooke's law; negative sign indicates force opposes displacement.

Flashcard 72: Identify the net force on an object in equilibrium.

Answer: Net force is 0 N. In equilibrium, all forces cancel out, resulting in zero net force.

Flashcard 73: Calculate the gravitational force on a 10 kg mass on Earth's surface.

Answer: $F = 98 \text{ N}$. Using $W = mg = 10 \times 9.8 = 98 \text{ N}$.

Flashcard 74: What is the formula for calculating weight?

Answer: $W = mg$. Weight equals mass times gravitational acceleration ($g = 9.8 \text{ m/s}^2$).

Flashcard 75: Identify the force that acts between two charged objects.

Answer: Electrostatic force. Coulomb force between charges; can be attractive or repulsive.

Flashcard 76: Find the net force if an object has forces of 5 N and 3 N in opposite directions.

Answer: Net force is 2 N in the direction of the larger force. Subtract opposing forces: $5 \text{ N} - 3 \text{ N} = 2 \text{ N}$.

Flashcard 77: What is the relationship between acceleration and net force?

Answer: Directly proportional. From Newton's second law: $a = \frac{F}{m}$.