What is a force?
Forces are just pushes and pulls in a particular direction.
What are the two types of forces?
- Contact forces (e.g., friction, air resistance)
- Non-contact forces (e.g., gravitational, magnetic).
What is a resultant force?
The overall force acting on an object when all forces are combined.
What happens when the resultant force is zero?
The object will remain balanced
What is weight, and how is it calculated?
- Weight is the force of gravity on an object
- Calculated as W = mg (weight = mass × gravitational field strength).
What is the difference between scalar and vector quantities?
- Scalars have only magnitude (e.g., distance, speed)
- Vectors have both magnitude and direction (e.g., velocity, force).
Is force a scalar or a vector?
A vector because it has both size and direction.
What is a Contact Force?
Occur when two objects are touching each other
What is a Non-Contact Force?
Act at a distance (without the two objects touching)
What are examples of a Contact Force?
- Friction
- Air Resistance
- Tension
What are examples of Non-contact forces?
- Gravitational force
- Electrostatic force
- Magnetic force
How do you calculate the resultant force when two forces act in the same direction?
Add their magnitudes together.
How do you calculate the resultant force when two forces act in opposite directions?
Subtract the smaller force from the larger one.
What happens if forces are balanced?
The object stays still or moves at a constant velocity.
What is deformation?
A change in the shape of an object due to
- stretching
- squashing (compression)
- bending
- twisting.
What is elastic deformation?
When an object returns to its original shape and size after forces are removed.
What is inelastic deformation?
When an object does not return to its original shape or size after forces are removed.
What is elastic potential energy?
The energy stored in an object when it is stretched or compressed.
What is the equation for elastic potential energy?
Ee = ½ ke², where:
Ee = elastic potential energy (J),
k = spring constant (N/m),
e = extension (m).
What is the equation for force applied to a spring?
F = ke, where:
F = force applied (N),
k = spring constant (N/m),
e = extension (m).
What does the spring constant represent?
The stiffness of the spring (higher values mean a stiffer spring).
What happens if a spring is stretched beyond its limit of proportionality?
It will not return to its original shape.
What does a straight-line section on a force-extension graph show?
The force is proportional to the extension (Hooke’s Law applies).
What happens after the limit of proportionality is reached?
The extension is no longer proportional to the force applied, and permanent deformation may occur.
