orbits

What is an orbit

The curved path of one celestial object or space craft around another celestial object

What is the moon’s instantaneous velocity

1023 m/s

Why does the moon orbit the earth without going off into space or getting pulled in towards the earth

Newtons 1st law- an object travelling at a certain velocity will continue to travel at that velocity unless acted Upton by a resultant force

• if moon is travelling at its instantaneous velocity it should continue to travel at that speed and direction forever, however bc the earth is so massive and close to the moon it exerts a strong gravitational pull (attractive force towards the earth)

• Bc the moon is quite big and travelling very fast it has a lot of momentum in forward direction so the gravitational force isn’t strong enough to pull it in towards the earth can only change its direction slightly

• As earth always applying gravitational force it’s always changing the moons direction

• Even through the speed of the moon is always the same it’s constantly changing direction and velocity (vector quantity speed and direction) always changing - everytime moon changes direction it’s accelerating

What is a steady orbit determined by

Both the instantaneous velocity of the orbiting object and the gravitational pull of the larger object both together

What is the relationship between the size of the objects orbit and speed

The smaller the objects orbit is , the faster the object must be travelling to maintain a stable orbit( or it will be sucked into the object it’s orbiting )

What happens if you pull the moons orbit closer to the earth- how can you avoid this

The distance between the earth and moon is much smaller -so the size of the gravitational force will be much greater and so if nothing changed the moon will get sucked into towards the earth

• To avoid this the moon will have to start travelling much faster so that it’s instantaneous velocity increased which will allow it to maintain a stable orbit and not be pulled in towards the earth

Are objects in orbit accelerating? Explain. 

Yes, objects in orbit are accelerating, as their direction is constantly changing, which means their velocity is changing.

Any change in velocity is considered acceleration (even if the speed remains the same).