Blog Title: Newton's Three Laws of Motion.

Newton's first law:

Things in motion will keep going until a force such as friction will slow them down until they slow down

Example: If a car was going along a road and its engine was off, the car will eventually stop because of the friction between the road and tyres. If a rocket was pushed into outer space it'll keep going because no force is there to stop it.

Newtons second law:

Things with a heavier mass will accelerate slower than a thing with a lighter mass.

Example: If two skateboards are pushed by the same time and one of them has a load of books on it, the one with no weight will go further.

f=ma Force= Mass x Acceleration

Work and Machines worksheet

13.4 Pg 80

1a) What is work? using a force to move an object
1b) A Machine: Anything which makes it easier to do work

2a) Pushing a Mower: Yes because you use the 'push' force to move the mower.
2b) Cleaning your teeth: Yes because you are using the 'push' force to move the brush around your teeth
2c) Cycling: Yes because you're moving your legs with the pedals and arms when you steer the bicycle.
2d) Reading: No because you're not using a force.

3) Why you need food for using force: Energy to keep your body functioning.

4) How to simple machines help: They help unscrewing nuts, opening cans, cutting wire and lifting cars which are things we would use a lot of energy on but with these machines we only need to use a little force.

5) other simple machines: Wheel/Axle, Nail, Carjack.

Pg. 81: 1-4

1) You need a set of pulley wheels and a rope for a pulley system
2) How does the pulley system easily lift the car engine: Because the pulley system divides the work into seperate ropes so each rope lifts a 100N. Another reason is because now there is a smaller force needed because of the greater distance.

3a) The chain: The chain is used as a rope like that of a pulley, you put the force on the chain it transmits the force to the wheels.

3b) The cycle's gears change the number of times that one turn of the crankshaft turns the back wheels.

4) Low gear helps you climb high places because the crank turns the back wheel once or twice which is enough to keep going up hill.

82 1-5: (TO BE COMPLETED)

What is a machine?

A machine is a man-made structure of a sort that helps in certain types of work; It does the same work as we would've done but instead it uses leverage to get the object to its destination. (e.g. pullies, ramps). It uses a longer distance but a smaller force meaning less work.

Erin Brokovich Review

The reason this picture relates to Erin Brokovich because it shows that companies, although they supply us electricity and other sources vital to our everyday life, they really are just doing it for the money and don’t care what happens to those around them. Such incidents have happened in Japan where the company was dumping mercury into the water poisoning the fish people ate and giving them weird diseases. These types of companies provide top quality sources for their recipients and all they’re concerned about is the electricity (or any other resource) reaching the recipients, their other actions are done regardless of taking the impact it will have on the lives of others. I always thought that these companies were very cautious about dumping waste and they’d do it in an environment friendly way. Turns out that some of them don’t even care about the environment and only for the money. So a lawsuit has to be put against them to hopefully persuade them, if not force them to stop threatening the lives of others.

Force Review

What is a force?

A force can be a push or a pull.

Can change the appearance of an object.

Can move in different directions.

Name 4 examples of forces and explain:

Gravity:

Is a force that has "pulled" us to the ground, the bigger the mass of the object using it, the greater the force.

Friction:

When two surfaces rub against each other, friction is formed. It slows down the speed of cars when the tires rub against the road. Thus it can slow down the speed of the rubbing objects.

Magnetic Force:

It can attract two magnetic metals depending on what pole the two magnets are classified as. Magnetic force attracts north and south poles together. Repels two of the same kind of poles.

Acceleration:

Acceleration is basically the speed something travels at. The acceleration can be slow, fast, moderate, and can cause the object to move in any direction.

Units of Force:

Force is measured in Newtons

Equation of Force:

Mass(kg, etc.)*Acceleration(km/h, etc.)= Force(N)