Term
What shape is the orbit of a planet? 

Definition


Term
State three ways the centripetal force can be increased. 

Definition
 By increasing the mass of the object
 By increasing the speed of the object
 By decreasing the radius of the circle



Term
What is the name of the resultant force causing acceleration towards the centre of a circle? 

Definition


Term
What does changing the acceleration of the object do? 

Definition
It changes the direction of the object's motion. 


Term
What is the centripetal force on a whirling ball? 

Definition
The tension force on the string. 


Term
What is the centripetal force on a turning car? 

Definition
The friction force on its tyres. 


Term
When the distance between two objects increases, what happens to the force of gravity acting on them? 

Definition
It decreases  the two factors are inversely proportional. 


Term
To stay in orbit at a particular distance, objects must ______________________________. 

Definition
To stay in orbit at a particular distance, objects must orbit at a particular speed which balances the gravitational force. 


Term
The greater the mass of two objects, the ______ the force between them. 

Definition
The greater the mass of two objects, the greater the force between them. 


Term
If you double the distance between two objects, what happens to the force between them? 

Definition
The original force is divided by 4. 


Term
When you increase the distance from the Sun, what happens to the time taken for one orbit? 

Definition


Term
What provides the centripetal force that keeps planets and satellites in orbit? 

Definition


Term
What planet in the Solar System has the greatest gravitational pull? 

Definition

