### Force and motion video lessons to buy

**Force and motion vdeo lessons to buy includes vectors, impulse and momentum, Newton's Laws of Motion, circular motion** **and gravitational fields. There is an example video at the bottom of the page**

**Adding vectors 4m40s**

An explanation of the definition of vector and scalar quantities and guidance through a simple rule for adding vectors with examples.

**Measuring the acceleration due to gravity**. 2m30s

A video of an experimental measurement with explanation and calculation.

**Newton's first law 1m50s (In GCSE, 14 to 16 years, collection also suitable for A level introduction)**

an illustrated explanation of the meaning of the law

**Newton's second law 4m30s (In GCSE, 14 to 16 years, collection also suitable for A level introduction)**

An explanation of the meaning of the law with experimental verification.

**Newton's Third law 2m30s (In GCSE, 14 to 16 years, collection also suitable for A level introduction)**

Using practical examples to explain the meaning of the law.

**Momentum – collisions. 4m (In GCSE, 14 to 16 years, collection also suitable for A level introduction)**

Explaining the conservation of momentum in both inelastic and elastic collisions.

**Momentum – rockets. 3m (In GCSE, 14 to 16 years, collection also suitable for A level introduction)**

Using examples to explain the conservation of momentum in rockets and explosions together with calculation of thrust from rate of change of momentum.

**Impulse and momentum (4.28m) (In GCSE, 14 to 16 years, collection also suitable for A level introduction)**

An explanation of the connection between force and the rate of change illustrated by simple experimentation kicking a football and with practical examples of application.

**Circular motion, gravity and charged particles in a magnetic field.**

The syllabus on circular motion and the examination questions asked are very often connected to examples based upon satellites and the motion of charged particles in a magnetic field. In this video list I have therefore included these topics with appropriate calculations. **The list of video tutorials is:**

**Angular velocity 3m 30s**

Explaining the concept of angular velocity to measure the rate of rotation in a circle and how it relates to speed and frequency.

**Circular motion equations 5m 40s (In GCSE, 14 to 16 years, collection also suitable for A level introduction)**

Explaining why there is acceleration and a force towards the centre and how these are calculated from the angular velocity and from the speed.

**Charged particles in a magnetic field 3m 30s**

How the force at right angles to the path of the particles leads to circular motion is explained and the connection between the size of this force and the force needed to maintain circular motion are equated to form an equation for the charge mass ratio of a charged particle such as an electron.

**The Inverse square Law 2m 40s**

The Inverse Square Law is the basis of Newton’s Law of gravitation but it also applies to a wide range of other situations; for example the intensity of radiation spreading from a source and the strength of an electric field. The video follows through a commonly used explanation of the reason for this relationship.

**Newton’s Law of Gravity 5m**

The law was a massive forward step in the development of our understanding of the way in which the Moon, the planets and the galaxy stay in a stable rotating state. Even with its imperfect explanation, superseded by Einstein and others, the theory is still used to give a good measure and understanding of the effects of gravity in most situations. The video sets out to describe and illustrate the basic concepts in a clear and concise manner.

**Gravitational potential and gravitational potential energy 4m 45s**

When we calculate changes in gravitational potential energy over short distances near to the earth we use the simple equation “F = mgh”. However over larger distances the value of g varies. The video explains why and how changes in the gravitational field strength can be taken into account.

**Satellites – Geostationary and polar 5m (Some of this is in GCSE, 14 to 16 years, collection also suitable for A level introduction)**

Satellites usually fall into one of two types. Polar satellites, which generally have low orbits circling the earth in around 90 minutes and geostationary satellites, which have a high orbit around the equator, circling the Earth every 24 hours in the same direction as the Earth itself is rotating and thus staying above the same point of the Earths surface. The video describes clearly the rotation of the satellites, the common applications and the calculation of the orbit height of a geostationary satellite.