Table of Contents

- 1 Why there is no torque with the rotation of the Earth?
- 2 Is there any torque on Earth?
- 3 What is reason that torque on planet due to gravitational force is zero?
- 4 How do you get zero torque?
- 5 What happens when there is no torque?
- 6 Why is the torque about the sun zero?
- 7 Why does torque become zero when net force on the body is zero?
- 8 Why is there no torque on the Sun?
- 9 Why is the external torque zero in case of planetary motions?

## Why there is no torque with the rotation of the Earth?

The Earth rotates about its axis, so that the Earth ‘moves’ to the East. But this motion if as result of angular momentum; no applied torque is causing or driving it.

### Is there any torque on Earth?

Answer: Net force (gravitational) acting on the earth due to other planets is negligible as explained below. Since torque is proportional to force, net torque acting on earth due to other planet is also negligible. Due to all these factors, net force and torque actin on earth due to other planets is negligible .

#### What is reason that torque on planet due to gravitational force is zero?

This is because both the gravitational force and the positional vector lie along the same line from the sun to the planet. As a rule, cross product of two parallel vectors is zero.

**What is the value of torque on the planet?**

Zero

Zero value of torque on the planet due to the gravitational force of sun.

**What is a torque in physics?**

torque, also called moment of a force, in physics, the tendency of a force to rotate the body to which it is applied.

## How do you get zero torque?

An applied force can result in zero torque if there is no lever arm or the applied force is parallel to the lever arm (see Figure 3 and 4 below).

### What happens when there is no torque?

Because there is no net torque acting on an object in equilibrium, an object at rest will stay at rest, and an object in constant angular motion will stay in angular motion. Because the net torque is equal to zero, the torques in Example 1 are balanced and acting in equilibrium.

#### Why is the torque about the sun zero?

The torque is zero because the gravitational force is radial in nature: i.e., its line of action passes through the Sun, and so its associated lever arm is of length zero. Figure 106: The origin of Kepler’s second law.

**What is torque explain?**

Torque is a measure of how much a force acting on an object causes that object to rotate. In other words, torque is the cross product between the distance vector (the distance from the pivot point to the point where force is applied) and the force vector, ‘a’ being the angle between r and F.

**At what angle is torque zero?**

the torque on a body will be zero if the angle between r and F is 0 or 180 degrees.

## Why does torque become zero when net force on the body is zero?

Theoretically if displacement occurs after applying force then there is torque which is more than force but if we apply force and there is no displacement then torque is zero. We can see in circular motion .As we know displacement is zero in circle so torque is always zero whether force is applied or not.

### Why is there no torque on the Sun?

Hence there is no torque on the planet with respect to the Sun. As there is no external force applied on Earth, the Sun has a greater grativitional force compared to the torque generated by earth revolution. Where are the current COVID-19 hotspots in the US?

#### Why is the external torque zero in case of planetary motions?

In the case of planetary motion the position vector of a planet from the sun and the force on the planet due to the sun (gravitational force) are parallel vectors as both lie along the line from the planet to the Sun. Cross product of parallel vectors is 0. Hence there is no torque on the planet with respect to the Sun.

**Why is the sum of torques always the same?**

Change the downward force to 2 N and try it again, only to see the sum of torques is the same regardless of point of consideration. BTW: In dynamics, the sum of torque is always taken about the center of mass, in order to yield the correct angular acceleration, because the sum of forces is generally not zero.