⇒ A force acting on an object can cause it to change shaoe and stretch, squash or bend

⇒ Weight is the pull of gravity on an object and can be calculated using the formula: W = mg

• Where W is the weight in N
• m is the mass of the object in kg
• g is the gravitational field strength in N kg^-1

⇒ Work done (or energy transferred) by a force on an object depends on the magnitude of the force in the direction of motion of the object. THis can be calulated using the formula: W = F s cosθ

• Where W is the work done in J
• F is the magnitude of the force in N
• s is the distance moved in the direction of the force in metres
• θ is the angle between the force and the direction which the object moves

⇒ People have been using, and altering, the properties of materials since the Stone Age

• Flint tools, samurai swords, and glass beakers all made use of the strength, flexibility or optical properties of materials to develop novel materials, and find new uses for old ones

⇒ Today, engineering materials researchers use their knowledge of the properties of materials to develop novel materials and find new uses for old ones

⇒ Also see our notes on:

• Density
• Hooke's Law
• Stress and the Young Modulus