3.4 Physics Mechanics

What is centre of mass/gravity?

Centre of mass is the point where the total mass is considered to act. It is the meeting point of the objects if left due to the influence of gravity alone.

What does a single force through the centre of mass cause?

Pure translation

What will a single force away from the centre of mass cause?

rotation and translation

In a centre of mass question, which mass should you make m1?

The object from which you want to the know the distance to the centre of mass.

In a centre of mass question, which value will always be 0m?

x1

Fill in the gaps:

If __ __________ forces act, if the centre of ____ is stationary, it will ______ __________.

If no unbalanced forces act, if the centre of mass is stationary, it will remain stationary.

Fill in the gaps:

When the centre of mass is __________:

If A (or B) _____ then both objects ____ and meet at the ______ __ ____. This means the ____ massive object will move ______ as it has a _______ distance to travel to reach the centre of mass at the ____ time as the ____ _______ object.

When the centre of mass is stationary:

If A (or B) pulls in then both objects move in and meet at the centre of mass. This means the least massive object will move faster as it has a greater distance to travel to reach the centre of mass at the same time as the more massive object.

Fill in the gaps:

If an object is moving at a ________ ________ it will ________ to move at a ________ velocity.

If an object is moving at a constant velocity it will continue to move at a constant velocity.

Fill in the gaps:

If the centre of mass is ____________ it will ________ ____________.

If the centre of mass is accelerating, it will continue accelerating.