Energy is a significant quantity in all branches of physics, largely because it is conserved. These slides introduce energy, specifically the kinetic energy of a moving object. The conservation of energy is used to relate kinetic energy to ‘work’. Work is a measure of how much energy is associated with the action of a force. Some questions are also included.

# Category Archives: moving about

# Mass and weight

These brief slides explain the difference between mass (measured in kilograms) and weight (which is a force, measured in newtons). Some relevant questions are also provided.

# Circular motion

These slides give a quick overview of centripetal (and centrifugal) force, as well as a few questions applying these concepts. Equations for centripetal force and centripetal acceleration are given.

# Adding Vectors

The addition of vectors is very useful for solving problems when more than one vector is involved in a calculation. This would include situations where multiple forces are acting, situations where we consider multiple velocity components, and situations where an object is displaced more than once.

Vector addition allows us to reduce *many vectors* into *one equivalent vector*, thus simplifying the problem to be solved. These slides outline vector addition and apply it to Newton’s second law. Sample problems are provided to determine the resultant force (net force), resultant velocity and total displacement.

# Acceleration and force

We often measure how things change over time. When we measure how *position* changes over time, this is called velocity. If we measure how *velocity* changes with time, it is called acceleration. Acceleration is present whenever there is a change in velocity.

The slides cover acceleration, and it’s relationship with force through Newton’s first and second laws. Relevant equations are introduced.

# Velocity and speed

These slides briefly outline the difference between speed and velocity. Relevant equations used to calculate these quantities are also introduced.

# Vectors, distance and displacement

Mechanics is the study of motion. One of the most important quantities to consider in mechanics is *where something is* in relation to another point. This is called displacement and is a vector quantity – which means it has both magnitude (how far away) and direction.

These slides outline the quantities *distance* and *displacement*, and also introduce the concept of vectors (and their opposite – scalars).