Understanding How Torque Works

Summary

This video explains the concept of torque, its role in the turning effect of forces, and how it is influenced by both the applied force and the perpendicular distance from the pivot. Using the example of a door, the script illustrates how torque can be calculated and how it affects movement. The principle of torque is also discussed, highlighting its importance in maintaining equilibrium, such as in a beam balance used to measure the weight of objects. The video provides a clear understanding of torque’s significance in rotational motion and the conditions of equilibrium.

Takeaways

• 😀 Torque is the turning effect produced by a force applied at a distance from the axis of rotation.
• 😀 Torque is calculated using the formula: τ = F × d, where F is force (in Newtons) and d is the perpendicular distance (in meters).
• 😀 The SI unit for torque is Newton-meter (Nm), as it is a product of force (N) and distance (m).
• 😀 Torque is a vector quantity, meaning it has both magnitude and direction, which can cause clockwise or anti-clockwise rotation.
• 😀 The principle of torque, or principle of moments, states that in equilibrium, the sum of clockwise moments equals the sum of anti-clockwise moments.
• 😀 In a beam balance, when the clockwise and anti-clockwise moments balance out, the object is in equilibrium.
• 😀 The mass of an object can be determined using the principle of torque. For example, if 3 calibration weights balance the oranges, their total mass equals that of the oranges.
• 😀 Weight is the force due to gravity acting on an object, which is the product of mass and acceleration due to gravity (mg).
• 😀 When calculating torque in a balance system, the torque on each side is determined by multiplying the weight by the distance from the pivot.
• 😀 An object is in **equilibrium** when both the sum of forces and the sum of torques acting on it are zero, meaning it does not move or rotate.

Q & A

What is torque?

Torque, also known as moment of force, is the turning effect produced when a force is applied at a distance from the axis of rotation of an object.

Why do we require more effort to pull a door handle when it's near the hinge?

More effort is required because the torque is smaller when the distance (perpendicular distance from the hinge) is shorter. Torque is directly proportional to this distance, meaning the closer the force is applied to the hinge, the less the turning effect.

How is torque calculated?

Torque is calculated using the formula τ = F × d, where F is the applied force in Newtons and d is the perpendicular distance from the axis of rotation in meters.

What is the SI unit for torque?

The SI unit for torque is Newton-meters (Nm), as it is the product of force in Newtons and distance in meters.

What is the principle of torque?

The principle of torque, also known as the principle of moment, states that when a body is in equilibrium, the sum of the clockwise moments equals the sum of the counterclockwise moments about a pivot.

How is the principle of torque applied in a beam balance?

In a beam balance, the principle of torque ensures that the torque from the calibration weights on one side of the pivot equals the torque from the object being measured (e.g., oranges) on the other side, leading to a balanced system.

What formula is used to calculate the mass of an object using a beam balance?

The mass of an object is calculated by equating the torques: mass of oranges × acceleration due to gravity × perpendicular distance = mass of calibration weights × acceleration due to gravity × perpendicular distance.

How does the concept of equilibrium apply to torque?

In equilibrium, the sum of all forces acting on an object is zero, and similarly, the sum of all torques (moments) must also be zero. This ensures that the object remains stationary without rotating.

What happens if the clockwise and counterclockwise moments are not equal?

If the clockwise and counterclockwise moments are not equal, the object will rotate around the pivot, and it will not be in equilibrium.

Why is torque considered a vector quantity?

Torque is considered a vector quantity because it has both magnitude (how much turning effect it produces) and direction (the direction of rotation, either clockwise or counterclockwise).