AP Physics 1 Flashcards: Torque

What this deck covers

This deck focuses on Torque, 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 effect on torque if $\theta$ changes from $90^\circ$ to $0^\circ$.

Answer: Torque decreases to zero. Maximum torque at $90°$ reduces to zero at $0°$.

Flashcard 2: What happens to torque if the angle is decreased from $90^\circ$?

Answer: Torque decreases. Smaller angles reduce $\sin(\theta)$, decreasing rotational effect.

Flashcard 3: What happens to torque if the force increases?

Answer: Torque increases. Torque is directly proportional to applied force magnitude.

Flashcard 4: Calculate torque for $r=3$ m, $F=10$ N, $\theta=60^\circ$.

Answer: $\tau = 25.98$ Nm. $\tau = 3 \times 10 \times \sin(60°) = 30 \times 0.866 = 25.98$ Nm.

Flashcard 5: What is the effect of perpendicular force application on torque?

Answer: Maximizes torque. Perpendicular application gives $\sin(90°) = 1$, the maximum value.

Flashcard 6: Which direction is positive torque conventionally?

Answer: Counterclockwise. Standard physics convention for positive rotational direction.

Flashcard 7: Identify the unit of torque in the SI system.

Answer: Newton-meter (Nm). Force times distance gives units of energy per radian.

Flashcard 8: Identify the unit of torque in the SI system.

Answer: Newton-meter (Nm). Force times distance gives units of energy per radian.

Flashcard 9: Choose the result when a force acts at the pivot point.

Answer: Torque is zero. At the pivot point, the lever arm distance $r = 0$.

Flashcard 10: What is the effect of negative torque on rotation?

Answer: Causes clockwise rotation. Negative torque produces rotation opposite to positive direction.

Flashcard 11: State the torque if $F=8$ N, $r=0.5$ m, and $\theta=90^\circ$.

Answer: $\tau = 4$ Nm. $\tau = 8 \times 0.5 \times \sin(90°) = 8 \times 0.5 \times 1 = 4$ Nm.

Flashcard 12: Identify the symbol for torque in equations.

Answer: $\tau$. Greek letter tau is the standard physics symbol for torque.

Flashcard 13: State the torque if $F=8$ N, $r=0.5$ m, and $\theta=90^\circ$.

Answer: $\tau = 4$ Nm. $\tau = 8 \times 0.5 \times \sin(90°) = 8 \times 0.5 \times 1 = 4$ Nm.

Flashcard 14: Find the torque for $r=2$ m, $F=5$ N, $\theta=30^\circ$.

Answer: $\tau = 5$ Nm. $\tau = 2 \times 5 \times \sin(30°) = 2 \times 5 \times 0.5 = 5$ Nm.

Flashcard 15: Find torque: $r=3$ m, $F=15$ N, $\theta=90^\circ$.

Answer: $\tau = 45$ Nm. $\tau = 3 \times 15 \times \sin(90°) = 3 \times 15 \times 1 = 45$ Nm.

Flashcard 16: What does $r$ represent in the torque formula?

Answer: Distance from pivot point to force application. The lever arm length determines how much turning advantage you have.

Flashcard 17: Find the torque for $r=2$ m, $F=5$ N, $\theta=30^\circ$.

Answer: $\tau = 5$ Nm. $\tau = 2 \times 5 \times \sin(30°) = 2 \times 5 \times 0.5 = 5$ Nm.

Flashcard 18: When is the torque zero?

Answer: When $\theta = 0^\circ$ or $\sin(\theta) = 0$. Force parallel to lever arm produces no rotational effect.

Flashcard 19: What does $\tau$ represent in the torque formula?

Answer: Torque. Greek letter tau represents the rotational moment or turning effect.

Flashcard 20: What is the torque if $F=0$?

Answer: Zero. No force means no rotational effect can be produced.

Flashcard 21: Identify the direction of torque for negative angle.

Answer: Clockwise. Negative angles conventionally indicate clockwise rotation direction.

Flashcard 22: State the effect of doubling $r$ on torque if $F$ and $\theta$ are constant.

Answer: Torque doubles. Torque is directly proportional to lever arm length.

Flashcard 23: What is the effect of perpendicular force application on torque?

Answer: Maximizes torque. Perpendicular application gives $\sin(90°) = 1$, the maximum value.

Flashcard 24: What happens to torque if the force increases?

Answer: Torque increases. Torque is directly proportional to applied force magnitude.

Flashcard 25: State the effect on torque if the force is perpendicular to the lever arm.

Answer: Torque is maximized. Perpendicular force gives $\sin(90°) = 1$, the maximum torque.

Flashcard 26: What is the formula for torque?

Answer: $\tau = r \cdot F \cdot \sin(\theta)$. Fundamental formula where all three factors determine rotational effect.

Flashcard 27: Which quantity is vector: force, mass, or torque?

Answer: Torque. Torque has both magnitude and direction, making it a vector.

Flashcard 28: What is the net torque if equal and opposite torques are applied?

Answer: Zero. Equal magnitude opposite torques cancel each other out.

Flashcard 29: What is the torque if $r=0$?

Answer: Zero. No lever arm means no rotational advantage or effect.

Flashcard 30: Calculate torque for $r=1.5$ m, $F=20$ N, $\theta=45^\circ$.

Answer: $\tau = 21.21$ Nm. $\tau = 1.5 \times 20 \times \sin(45°) = 30 \times 0.707 = 21.21$ Nm.

Flashcard 31: Identify the factor that does not affect torque.

Answer: Mass of the object. Mass affects weight but not the geometric torque relationship.

Flashcard 32: Choose the effect of increasing $r$ on torque.

Answer: Torque increases. Torque is directly proportional to lever arm distance.

Flashcard 33: State the right-hand rule in torque context.

Answer: Curl fingers in rotation direction; thumb points in torque direction. Standard method to determine torque vector direction in 3D.

Flashcard 34: Calculate torque for $r=1.5$ m, $F=20$ N, $\theta=45^\circ$.

Answer: $\tau = 21.21$ Nm. $\tau = 1.5 \times 20 \times \sin(45°) = 30 \times 0.707 = 21.21$ Nm.

Flashcard 35: What is the torque direction for a positive angle?

Answer: Counterclockwise. Positive angles correspond to counterclockwise rotation by convention.

Flashcard 36: Identify the factor that does not affect torque.

Answer: Mass of the object. Mass affects weight but not the geometric torque relationship.

Flashcard 37: Calculate torque: $r=1$ m, $F=10$ N, $\theta=45^\circ$.

Answer: $\tau = 7.07$ Nm. $\tau = 1 \times 10 \times \sin(45°) = 10 \times 0.707 = 7.07$ Nm.

Flashcard 38: What is the torque if $F=0$?

Answer: Zero. No force means no rotational effect can be produced.

Flashcard 39: Calculate the torque if $r=2$ m, $F=10$ N, $\theta=0^\circ$.

Answer: $\tau = 0$ Nm. $\sin(0°) = 0$, so torque equals zero regardless of $r$ and $F$.

Flashcard 40: What does $F$ represent in the torque formula?

Answer: Magnitude of the force applied. The force magnitude directly affects the rotational strength.

Flashcard 41: Find the angle for zero torque if $r=4$ m and $F=7$ N.

Answer: $\theta = 0^\circ$ or $180^\circ$. When force is parallel to lever arm, $\sin(\theta) = 0$.

Flashcard 42: Find the net torque: $\tau_1=5$ Nm, $\tau_2=-3$ Nm.

Answer: $\tau_{net} = 2$ Nm. Vector addition: $5 + (-3) = 2$ Nm in positive direction.

Flashcard 43: What happens to torque if the angle is decreased from $90^\circ$?

Answer: Torque decreases. Smaller angles reduce $\sin(\theta)$, decreasing rotational effect.

Flashcard 44: State the relationship between torque and rotational equilibrium.

Answer: Net torque must be zero. No net torque means no angular acceleration occurs.

Flashcard 45: Find the net torque: $\tau_1=5$ Nm, $\tau_2=-3$ Nm.

Answer: $\tau_{net} = 2$ Nm. Vector addition: $5 + (-3) = 2$ Nm in positive direction.

Flashcard 46: When is the torque zero?

Answer: When $\theta = 0^\circ$ or $\sin(\theta) = 0$. Force parallel to lever arm produces no rotational effect.

Flashcard 47: What does $\tau$ represent in the torque formula?

Answer: Torque. Greek letter tau represents the rotational moment or turning effect.

Flashcard 48: What does $\theta$ represent in the torque formula?

Answer: Angle between force and lever arm. This angle determines the effective component of force causing rotation.

Flashcard 49: Calculate the torque if $r=2$ m, $F=10$ N, $\theta=0^\circ$.

Answer: $\tau = 0$ Nm. $\sin(0°) = 0$, so torque equals zero regardless of $r$ and $F$.

Flashcard 50: Which direction is positive torque conventionally?

Answer: Counterclockwise. Standard physics convention for positive rotational direction.

Flashcard 51: Find torque: $r=3$ m, $F=15$ N, $\theta=90^\circ$.

Answer: $\tau = 45$ Nm. $\tau = 3 \times 15 \times \sin(90°) = 3 \times 15 \times 1 = 45$ Nm.

Flashcard 52: What is the net torque if equal and opposite torques are applied?

Answer: Zero. Equal magnitude opposite torques cancel each other out.

Flashcard 53: Find the lever arm if torque is $20$ Nm and force is $5$ N.

Answer: $r = 4$ m. From $\tau = rF\sin(\theta)$, assuming $\theta = 90°$: $r = \tau/F = 20/5 = 4$ m.

Flashcard 54: Calculate torque: $r=1$ m, $F=10$ N, $\theta=45^\circ$.

Answer: $\tau = 7.07$ Nm. $\tau = 1 \times 10 \times \sin(45°) = 10 \times 0.707 = 7.07$ Nm.

Flashcard 55: Calculate torque for $r=3$ m, $F=10$ N, $\theta=60^\circ$.

Answer: $\tau = 25.98$ Nm. $\tau = 3 \times 10 \times \sin(60°) = 30 \times 0.866 = 25.98$ Nm.

Flashcard 56: State the relationship between torque and rotational equilibrium.

Answer: Net torque must be zero. No net torque means no angular acceleration occurs.

Flashcard 57: What effect does increasing $\theta$ to $90^\circ$ have on torque?

Answer: Torque increases. Approaching $90^\circ$ increases $\sin(\theta)$ toward its maximum value.

Flashcard 58: State the condition for maximum torque.

Answer: $\theta = 90^\circ$ or $\sin(\theta) = 1$. Perpendicular force application maximizes the rotational effect.