Newton's three laws of motion where created when an apple fell on his head. The first law of motion is when an object is in motion, it will always stay in motion. On the other hand when an object is at rest,it will always stay at rest unless a force acts on it. when an object is moving, all in it and on it will move in the same speed. If the object suddenly stops, the other objects will keep on moving until stopped by another force acting on it. Even though it was said by newton if an object moves, it will remain moving does not happen in our world is because of friction. Friction is produced when two rough surfaces rub together.
The second law of motion is when an object has an unbalanced force acting on it will accelerate in the direction of that force. An example is when you are sitting on the top of a slide. You will not move because gravity is pulling you down, on the other hand the slide is pushing you up which cancels out the forces. But if you push, you will then slide down because even though the air resistance is acting on you along with friction,the majority of force is gravity because you are on a slope and so you will use your mass to gain more speed and gravity advantage.
Newton's third law of motion is forces always occur in equal and opposite pairs. So if you are pushing a door, the door will move and you will move as well. That does not happen because of the friction between our feet and the floor which combines your mass with the floor's or building's mass. However, if you tried it with your roller skates, you will go back because there is less friction happening since roller skates have less rough surfaces and since its a small wheel, there is less surface touching ot making a contact with the floor which reduces the amount of friction.
Saturday, February 27, 2010
Monday, February 15, 2010
Simple Machines
Work and machines
1- What is meant by doing:
a- Work: Is using a force to move an object.
b- Machines: Is anything which makes work easier to do.
2-Are you doing work when you are:
a-Pushing a Mower: Yes because you are transferring energy from one object to another.
b-cleaning your teeth: Yes because you are transferring energy from your arm to the brush while you move it up and down.
c- Cycling: Yes because you are moving your legs in a circular motion to transfer your energy from your body to the bike.
3-Why must you eat if you are doing work?
Work is transferring your energy from your body to the certain object. Because Work consumes energy, you will need a replacement for it and so food can be made into energy after being digested and through your intestines to merge with your blood and become energy.
4- Why are spanners, pliers, and can openers called machines?
Since machines are any device or anything that makes work easier, the following objects do make work easier. For example, it is easier to use can opener rather than smashing it or opening it with your hands.
5- Give other names of simple machines.
Knife, scissors, cutter and screw drive.
Pulleys, gears and other wheels
1- What do you need to make a pulley system?
To make a pulley, it is required to have two wheels and a rope, a hooker to hang it from up on a ceiling or anything equivalent.
2-two examples of why it is easier to lift an engine with a pulley.
first reason is when he pulls the pulley down, it is easier to pull down rather than lifting it up to your chest
second reason is when you pull down, you are using your weight as well rather than your arm force only. This way the weight or pressure distribute on some parts of your body and will give you a boost for your force.
3- What is the job of:
a) the chain:The chain's job is transfer the power that is generated by your legs moving the peddles to the wheels in the bike.
b) The gears on a bicycle: The cycle's gear changes the number of times that one turn of the crankshaft turns the back wheel
4-What is the difference between the cycle in high gear and low gear?
In high gear, the chain runs over a small cog wheel where it reduces the speed however, it increases the amount of turns and decreases the force you have to do. It is used for low roads, or in streets. In low gear, the chain uses the bigger cog wheel where it decreases the amount of turns and increases the force you have to do and increases your speed. It is used in high roads, mountains or simply when you need to speed up.
5- Other uses of pulleys??
Pulleys can be used to lift heavy weights to to the top. For example if you were trying to lift up an air-conditioner to the roof, you might think of using the pulley to ease your work. Pulleys are also used in theater where it is hooked to the curtains as well as our houses.
Building a pyramid
1- What is meant by doing:
a- Work: Is using a force to move an object.
b- Machines: Is anything which makes work easier to do.
2-Are you doing work when you are:
a-Pushing a Mower: Yes because you are transferring energy from one object to another.
b-cleaning your teeth: Yes because you are transferring energy from your arm to the brush while you move it up and down.
c- Cycling: Yes because you are moving your legs in a circular motion to transfer your energy from your body to the bike.
3-Why must you eat if you are doing work?
Work is transferring your energy from your body to the certain object. Because Work consumes energy, you will need a replacement for it and so food can be made into energy after being digested and through your intestines to merge with your blood and become energy.
4- Why are spanners, pliers, and can openers called machines?
Since machines are any device or anything that makes work easier, the following objects do make work easier. For example, it is easier to use can opener rather than smashing it or opening it with your hands.
5- Give other names of simple machines.
Knife, scissors, cutter and screw drive.
Pulleys, gears and other wheels
1- What do you need to make a pulley system?
To make a pulley, it is required to have two wheels and a rope, a hooker to hang it from up on a ceiling or anything equivalent.
2-two examples of why it is easier to lift an engine with a pulley.
first reason is when he pulls the pulley down, it is easier to pull down rather than lifting it up to your chest
second reason is when you pull down, you are using your weight as well rather than your arm force only. This way the weight or pressure distribute on some parts of your body and will give you a boost for your force.
3- What is the job of:
a) the chain:The chain's job is transfer the power that is generated by your legs moving the peddles to the wheels in the bike.
b) The gears on a bicycle: The cycle's gear changes the number of times that one turn of the crankshaft turns the back wheel
4-What is the difference between the cycle in high gear and low gear?
In high gear, the chain runs over a small cog wheel where it reduces the speed however, it increases the amount of turns and decreases the force you have to do. It is used for low roads, or in streets. In low gear, the chain uses the bigger cog wheel where it decreases the amount of turns and increases the force you have to do and increases your speed. It is used in high roads, mountains or simply when you need to speed up.
5- Other uses of pulleys??
Pulleys can be used to lift heavy weights to to the top. For example if you were trying to lift up an air-conditioner to the roof, you might think of using the pulley to ease your work. Pulleys are also used in theater where it is hooked to the curtains as well as our houses.
Building a pyramid
Sunday, February 14, 2010
Explain what a machine is in relation to work and force
A machine is a device that is consistent of different parts working together to accomplish a certain job or movement. However, a simple machine is a device is that goes in one direction. Machines are devices that are used to ease the work, one way is they increase the distance to decrease the force. The relation between machines or particularly simple machines to force is to make Joules (Work) easier to do because they increase the distance to decrease the force. The machines use the fromula distance over force to find the amount of work that is needed or done when using the machine.
A machine is a device that is consistent of different parts working together to accomplish a certain job or movement. However, a simple machine is a device is that goes in one direction. Machines are devices that are used to ease the work, one way is they increase the distance to decrease the force. The relation between machines or particularly simple machines to force is to make Joules (Work) easier to do because they increase the distance to decrease the force. The machines use the fromula distance over force to find the amount of work that is needed or done when using the machine.
Tuesday, February 9, 2010
What is a force?
A force is a push or a pull that can change the direction of the object or the shape/size of the object.
4 examples of force:
-Friction is a force happened by two surfaces rubbing together
-Pulling a wagon is another type force where it is a pull
-Gravity is a force. Gravity pulls you down to earth and it is a pulling force.
-compressing a spring is a push where you force it down.
Units of force?
Force is measured by newtons. Newtons measure the amount of force you are placing on earth, object, etc.
Equation of force?
The equation of a force is F=mass (x) acceleration
kg m/s2
A force is a push or a pull that can change the direction of the object or the shape/size of the object.
4 examples of force:
-Friction is a force happened by two surfaces rubbing together
-Pulling a wagon is another type force where it is a pull
-Gravity is a force. Gravity pulls you down to earth and it is a pulling force.
-compressing a spring is a push where you force it down.
Units of force?
Force is measured by newtons. Newtons measure the amount of force you are placing on earth, object, etc.
Equation of force?
The equation of a force is F=mass (x) acceleration
kg m/s2
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