Science Quiz - Forces 01 (Answers)
This KS3 Science quiz asks questions on forces. It doesn't matter if something is moving or stationary, there are always forces acting on it. The famous Scientist, Isaac Newton, realised this and came up with his three laws of motion. Forces are measured in newtons which have the symbol N. One of the most famous of Newton's laws is that if an object isn't moving, the forces acting on it are equal and opposite.
Imagine a book lying down on a shelf. The book puts a downward force on the shelf. The shelf must therefore be putting exactly the same force back on the book. Now if you add a whole lot more books to the shelf, if the shelf can't push back with the same force that the pile of books is putting on the shelf, it moves - in other words, it collapses! The force a book puts on a shelf is its weight. Weight is therefore measured in newtons. Unfortunately, in everyday life, you will hear most people referring to weight using kilograms. This is entirely incorrect, kilograms are a measure of mass. Weight is the force created by the attraction of gravity on the mass of an object. On Earth, a mass of 100g (0.1kg) has a weight of about 1N.
[/readmore]
|
|
||||||||||||||||||||||||
|
|
||||||||||||||||||||||||
|
|
||||||||||||||||||||||||
|
|
||||||||||||||||||||||||
|
|
You can find more about this topic by visiting BBC Bitesize - Forces and movement
Forces can act in any direction. When drawing forces, you must always show in which direction they are acting
|
Mass is measured in grams, kilograms etc
|
||||||||||||||||||||||||
Friction is a force
|
Weight is a force and therefore should be measured in newtons
|
||||||||||||||||||||||||
Unbalanced forces will ALWAYS create movement
|
This is Newton's third law of motion
|
||||||||||||||||||||||||
Magnets attract or repel at a distance, they do not need to touch the object they are acting on to have an effect
|
500g = 0.5kg, 0.5kg weighs 0.5 x 10 = 5N
|
||||||||||||||||||||||||
100g = 0.1kg, 0.1kg weighs 0.1 x 25 = 2.5N. The weight of an object depends on the force of gravity that is acting on it. The Moon has a gravity of about one sixth of that of the Earth, so 1kg would weigh a lot less than on the Earth, whilst on the planet Jupiter, it would weigh a lot more as the force of gravity there is larger
|
According to Newton's third law of motion, if the mass puts a force on the spring, the spring must be putting a force on the mass
|