# What two forces determine the size of a star?

## What two forces determine the size of a star?

The size of a star is a natural consequence of the balance between the inward pull of gravity and the outward pressure of radiation produced inside the star. When these two forces are balanced, the outer layers of the star are stable and said to be in hydrostatic equilibrium.

What maintains the shape of a star?

Gravity acts equally in all directions, and the gas is dispersed symmetrically around the center forming a shape of a perfect sphere… or at least almost perfect. Most stars are rotating around their axes at different speeds. The surface of our sun, for example, completes a rotation in 25 days.

### What forces are in balance to keep the shape of a star?

The inward force of gravity is balanced out by the outward force of pressure to keep the star stable. This stable balance, the outward pressure of hot gases balancing the inward pull of gravity is called the hydrostatic equilibrium.

What are the two opposing forces in a star?

gravity
The process of collapse takes between 10,000 and 1,000,000 years. A Star’s Life: A star’s life is an extended battle between two opposing forces: gravity and pressure. A star can maintain its internal pressure only if it continually generates energy to replace the energy that it radiates into space.

## Why are stars star shaped?

Why? Because in the Hubble Space Telescope, the smaller secondary mirror is held in position by four cross hair-like struts, and the incoming light has to travel past these struts to land on the bigger main mirror. This light gets bent, giving the star its characteristic four points.

What shape is a star in geometry?

By geometrical definition, a star is a regular polygon: simple or complex. Polygon – any two-dimensional shape formed with straight lines and is closed. Regular polygon – a polygon whose sides are all the same length (equilateral) and whose angles are all the same (equiangular).

### Which two forces can help a star maintain its equilibrium?

Pressure and gravity. Pressure due to fusion reactions pushes outwards. Gravity pulls inwards to keep the star in equilibrium.

What two forces oppose each other in a star that allow it to maintain its shape size and temperature for long periods of time?

While self-gravity pulls the star inward and tries to make it collapse, thermal pressure (heat created by fusion) pushes outward. These two forces cancel each other out in a main sequence star, thus making it stable.

## What type of shape is a star?

regular polygon
By geometrical definition, a star is a regular polygon: simple or complex. Polygon – any two-dimensional shape formed with straight lines and is closed. Regular polygon – a polygon whose sides are all the same length (equilateral) and whose angles are all the same (equiangular).

Are stars actually star shape?

A star is a giant spherical ball of plasma. Furthermore, all the stars that we can see (apart from our Sun) are so far away that they appear to us as perfect little dots. The answer to why we draw stars as pointy objects, is because our eyes actually see them as having points.

### What are the two major forces that act on a star?

What are the two major forces that act on a star? Pressure and gravity. Pressure due to fusion reactions pushes outwards. Gravity pulls inwards to keep the star in equilibrium. The mass of star causes gravity which pulls inwards. Pressure and temperature created by fusion of hydrogen to helium push it outwards.

How does the force of gravity keep a star stable?

The inward force of gravity is balanced out by the outward force of pressure to keep the star stable. This stable balance, the outward pressure of hot gases balancing the inward pull of gravity is called the hydrostatic equilibrium.

## How does the mass of a star keep it intact?

For a star, everything depends on its mass. Throughout their lives, stars fight the inward pull of the force of gravity. It is only the outward pressure created by the nuclear reactions pushing away from the star’s core that keeps the star “intact”.

What causes pressure and gravity in a star?

Pressure and gravity. Pressure due to fusion reactions pushes outwards. Gravity pulls inwards to keep the star in equilibrium. The mass of star causes gravity which pulls inwards. Pressure and temperature created by fusion of hydrogen to helium push it outwards.