By understanding forces and how they work, humans are able to design huge skyscrapers and funfair rides, they are able to make machines work more efficiently and they can keep satellites in orbit.
1. Knowing how different forces interact on the wing of an aeroplane.
2. Tension and compression forces are used in the design of huge skyscrapers.
3. A baker can measure the weight of the ingredients.
4. Oil can be used to reduce the force of friction.
5. The lever on a pump allows a relatively small push to create a much larger force.
6. A rollercoaster uses centripetal force to stop the car falling off the track when it does a loop-the-loop.
Match the application of forces in 1–6 to the personal, social and global importance list in A–F. A. Food tastes good
B. People can pump clean water from deep under ground by hand.
C. Thrill seekers can enjoy themselves safely.
D. People can travel from one side of the world to another in less than 24 hours.
E. More people can work in city centre locations.
F. Car engines don’t overheat as easily.
Chapter Summary 1.
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A force is anything which causes an object to move or change velocity (speed or direction). Force is measured in newtons. Newton’s first law of motion states that unless a force acts on it, an object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction. Friction is a force which prevents easy movement between two objects in contact. The rougher the two surfaces in contact are, the more friction there will be. Friction can be reduced using lubricants. Newton’s second law explains that when a force acts on mass it accelerates. The greater the force the greater the acceleration. Force (N) = Mass (kg) x Acceleration (m s-2
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Weight (N) = Mass (kg) x Acceleration due to gravity = Mass (kg) x 10 m s-2 Newton’s third law states that for every action there is an equal but opposite reaction.
