Forces and Motion

What is a force?

A push or a pull.

What’s the difference between vectors and scalars?

Vectors have both size/magnitude and direction whereas scalars only have a size/magnitude.

What is the resultant force?

The overall force on an object.

How do you calculate the resultant force?

If forces are in the same direction, add them together, if they’re in opposite directions, subtract the smallest one from the largestone.

What is happening if the resultant force is 0?

The object is either stationary or moving at a constant speed.

What do equal forces do to eachother?

Cancel eachother out.

What is Newton’s First Law?

A moving object will continue to move at a constant speed unless an external, unbalanced force acts on it.

What is velocity?

Velocity refers to the rate at which an object is moving and in which direction.

How are resultant forces and velocity linked?

The overall resultant force is what determines if the velocity of an object changes.

What ways are the resultant forces going for objects that are speeding up/slowing down?

If an object is slowing down the resultant force will go backwards, if it’s speeding up the resultant force will go forwards.

What is mass?

A measure of how much matter or particles an object has.

What is weight?

A measure of how strongly gravity pulls on an object’s matter.

What does a sideways resultant force do?

Make an object change direction.

What is centripetal force?

Centripetal force is the resultant force acting on an object moving in a circular path that acts towards the centre of the circle.

What are the units for acceleration?

Metres per second squared, or m/s².

How do you calculate acceleration?

Ending velocity - starting velocity divided by time

What is Newton’s Second Law?

The acceleration of an object in the direction of the resultant force depends on the size of the force and the mass of the object, or f =m x a.

What is inertial mass?

Inertial mass measures how difficult it is to change the velocity of an object.

What is Newton’s Third Law?

Whenever two objects interact, they exert equal and opposite forces on each other.

What are the two factors that affect momentum?

Velocity and mass.

What is momentum?

The measure of how hard it is to stop an object moving.

What is work done?

When an object is moved by a force and energy is transferred to it.

What is the calculation for work done?

Work done = force x distance moved in the direction of the force, or w = f x s