Hello!
Today we learnt about Energy and its Transformations and stuff during Physics. So basically...

-The law of conservation of energy states that energy cannot be created or destroyed. *TAKE NOTE!!!*

-Forms of Energy
Potential Energy | Heat Energy | Light energy | Kinetic Energy | Sound Energy | Electrical Energy
*Potential Energy (Chemical Potential Energy, Gravitational Potential Energy, Elastic Potential Energy)

-Energy Transformations
For example...
When we switch on the torchlight,
Chemical Potential Energy (from the batteries) → Electrical Energy → Light energy + Heat energy

Okay I'm going to stop here because I forgot to bring back my textbook and I can't remember what else we learnt SPECIFICALLY. So don't misunderstand me. I was paying attention in class. :)

The Moment of a force is a measure of its tendency to cause a body to rotate about a specific point or axis. This is different from the tendency for a body to move, or translate, in the direction of the force. In order for a moment to develop, the force must act upon the body in such a manner that the body would begin to twist. This occurs every time a force is applied so that it does not pass through the centroid of the body. A moment is due to a force not having an equal and opposite force directly along it's line of action.

Imagine two people pushing on a door at the doorknob from opposite sides. If both of them are pushing with an equal force then there is a state of equilibrium. If one of them would suddenly jump back from the door, the push of the other person would no longer have any opposition and the door would swing away. The person who was still pushing on the door created a moment.

All high heels counter the natural functionality of the foot, which can create skeleton/muscular problems if they are worn excessively. Stiletto heels are no exception, but some people assume that because they are thinner they must be worse for you. In fact, they are safer to wear than the other extreme of high heel fashion, the platform shoe. Despite their impracticality, their popularity remains undiminished - as Terry DeHavilland (UK shoe designer) has said, "people say they're bad for the feet but they're good for the mind. What's more important?"

Stiletto heels undoubtedly concentrate a large amount of force into a small area. The great pressure transmitted through such a heel (allegedly greater than that exerted by an elephant standing on one foot) can cause damage to carpets and floors. The stiletto heel will also sink into soft ground, making it impractical for outdoor wear on grass.

-taken from wikipedia.org

Tides are caused by a gravitational tug-of-war between the sun, moon, and earth. All objects exert gravitational pull on each other. The closer they are, or the larger they are, the greater the pull. All of the planets exert some gravitational pull on the earth. However, the pull of the moon and sun are most noticeable because the moon is so close to us and the sun is so big. It takes the earth 365 days to revolve around the sun. As it revolves around the sun, it spins, or rotates on its axis once every 24 hours. At the same time, the moon revolves around the earth once every 29 days. The gravitational pull of the sun holds the earth in orbit, while the gravitational pull of the earth keeps the moon in orbit. As a result of this gravitational attraction between the earth and the moon, the side of the earth facing the moon is pulled towards it. Solid objects like the ground and buildings are not distorted as much as liquids like the ocean. A bulge of water occurs on the side of the earth facing the moon. As the earth rotates around the sun, centrifugal force causes an equal bulge of water on the opposite side of the earth. Water is pulled away from these two sides of the earth to form these bulges, or high tides. This leaves a depression, or low spot, in the oceans between. These are the areas of low tides. Most areas of the earth have two high tides and low tides every day. These high and low tides are slightly more than 6 hours apart. In some areas, the high and the low tides are the same. However, the earth is tilted on its axis, so the bulges are sometimes unequal. Because of this, in the Southern California region, one of the high tides each day is higher and one of the low tides each day is lower than the other. It depends on where you are located in the earth’s surface whether your high and low tides are semidiurnal (the same tide twice a day) or semi diurnal mixed (different tides twice a day).

Taken from: http://www.usc.edu/org/seagrant/Education/IELessons/Docs/MoonAndTides.pdf

Q: What is a heart rate?
A: The average number of heart beats per minute; a heart beat is when the heart contracts to pump blood thru your system.

Q: What is a resting heart rate?
A: Resting heart rate is the number of beats in one minute while you are at a complete rest state. Your resting heart rate indicates your basic overall heart health and fitness level. The more conditioned your body is, the less effort it needs to make to pump blood thru your body.

Q: What is a recovery heart rate?
A: This is the heart rate your body will drop to after two minutes, after stopping an exercise session. For instance you exercised for 30 minutes and your heart rate was at 155. Two minutes after you stopped exercising, your heart rate then decreased to 95. This recovery heart rate measure helps to evaluate your overall heart fitness level. Use this measurement to compare between exercise sessions

Q: What is a maximum heart rate?
A: A maximum heart rate (Max HR) is the highest number of beats your heart contracts during a one minute measurement. Max HR is a useful tool to measure training intensities and typically is used to measure or predict the level of exercise. It's always good to measure your Max HR while doing exercises to ensure you stay within a safe range or use it to measure if the exercise is actually working well enough to raise your heart rate to acceptable ranges and levels.

Q: How do I measure a Max HR?
A: The best method of determining your individual maximum heart rate is to be clinically tested and monitored on a treadmill. This is called a treadmill stress testing and is done by a cardiologist or certified physical therapist. Based on your age and physical condition, a formula is used to predict your Max HR. The other method is by using an age-predicted maximum heart rate formula:

WOMEN: 226 - your age = age-adjusted Max HR
MEN: 220 - your age = age-adjusted Max HR

Example: If you are a 30-year-old woman, your age-adjusted maximum heart rate is 226- 30 years = 196 bpm (beats per minute).

*note that this formula allows you to estimate your Max HR. Be sure to consult with your exercise trainer and doctors for the most effective rates that are customized to your health.

Heart Rate Charts:
Heart Rate Chart: Babies to Adults
AGE Beats Per Minute (BPM)
Babies to Age 1 100 - 160
Children ages 1-10 60 - 140
Children age 10+ and adults 60 - 100
Athletes: 40 - 60

Taken from: http://www.heart.com/heart-rate-chart.html

A sphere is a three-dimensional circle. Or you could say that a sphere is the set of all the points that are at the same distance from the center of the sphere. In nature, centrifugal force and gravity tend to make a lot of things into spheres: soap bubbles, for instance, atoms, and planets.

The radius of a sphere is the distance from its center to any point on its surface. The surface area of a sphere is the set of all the points on the outside of the sphere. To figure out what the surface area of a sphere is, you multiply the radius by itself and then multiply that by pi, so the formula is 4πr2. This is because the area is the length times the width (just like the area of a square). The width of a sphere is its diameter (twice the radius, or 2r). The length of a sphere is its circumference (2πr). So the width times the length, or the area, is 2r times 2πr, or 4πr2.

To figure out the volume of a sphere (how much air or water it would take to fill it up), you multiply the radius by itself and then by itself again, and then by pi, and then by 4, and divide the whole thing by 3. So the formula for the volume of a sphere is 4πr3/3.

Source: http://www.historyforkids.org/scienceforkids/math/geometry/sphere.htm

Hello!
Today we learnt about Energy and its Transformations and stuff during Physics. So basically...

-The law of conservation of energy states that energy cannot be created or destroyed. *TAKE NOTE!!!*

-Forms of Energy
Potential Energy | Heat Energy | Light energy | Kinetic Energy | Sound Energy | Electrical Energy
*Potential Energy (Chemical Potential Energy, Gravitational Potential Energy, Elastic Potential Energy)

-Energy Transformations
For example...
When we switch on the torchlight,
Chemical Potential Energy (from the batteries) → Electrical Energy → Light energy + Heat energy

Okay I'm going to stop here because I forgot to bring back my textbook and I can't remember what else we learnt SPECIFICALLY. So don't misunderstand me. I was paying attention in class. :)

The Moment of a force is a measure of its tendency to cause a body to rotate about a specific point or axis. This is different from the tendency for a body to move, or translate, in the direction of the force. In order for a moment to develop, the force must act upon the body in such a manner that the body would begin to twist. This occurs every time a force is applied so that it does not pass through the centroid of the body. A moment is due to a force not having an equal and opposite force directly along it's line of action.

Imagine two people pushing on a door at the doorknob from opposite sides. If both of them are pushing with an equal force then there is a state of equilibrium. If one of them would suddenly jump back from the door, the push of the other person would no longer have any opposition and the door would swing away. The person who was still pushing on the door created a moment.

All high heels counter the natural functionality of the foot, which can create skeleton/muscular problems if they are worn excessively. Stiletto heels are no exception, but some people assume that because they are thinner they must be worse for you. In fact, they are safer to wear than the other extreme of high heel fashion, the platform shoe. Despite their impracticality, their popularity remains undiminished - as Terry DeHavilland (UK shoe designer) has said, "people say they're bad for the feet but they're good for the mind. What's more important?"

Stiletto heels undoubtedly concentrate a large amount of force into a small area. The great pressure transmitted through such a heel (allegedly greater than that exerted by an elephant standing on one foot) can cause damage to carpets and floors. The stiletto heel will also sink into soft ground, making it impractical for outdoor wear on grass.

-taken from wikipedia.org

Tides are caused by a gravitational tug-of-war between the sun, moon, and earth. All objects exert gravitational pull on each other. The closer they are, or the larger they are, the greater the pull. All of the planets exert some gravitational pull on the earth. However, the pull of the moon and sun are most noticeable because the moon is so close to us and the sun is so big. It takes the earth 365 days to revolve around the sun. As it revolves around the sun, it spins, or rotates on its axis once every 24 hours. At the same time, the moon revolves around the earth once every 29 days. The gravitational pull of the sun holds the earth in orbit, while the gravitational pull of the earth keeps the moon in orbit. As a result of this gravitational attraction between the earth and the moon, the side of the earth facing the moon is pulled towards it. Solid objects like the ground and buildings are not distorted as much as liquids like the ocean. A bulge of water occurs on the side of the earth facing the moon. As the earth rotates around the sun, centrifugal force causes an equal bulge of water on the opposite side of the earth. Water is pulled away from these two sides of the earth to form these bulges, or high tides. This leaves a depression, or low spot, in the oceans between. These are the areas of low tides. Most areas of the earth have two high tides and low tides every day. These high and low tides are slightly more than 6 hours apart. In some areas, the high and the low tides are the same. However, the earth is tilted on its axis, so the bulges are sometimes unequal. Because of this, in the Southern California region, one of the high tides each day is higher and one of the low tides each day is lower than the other. It depends on where you are located in the earth’s surface whether your high and low tides are semidiurnal (the same tide twice a day) or semi diurnal mixed (different tides twice a day).

Taken from: http://www.usc.edu/org/seagrant/Education/IELessons/Docs/MoonAndTides.pdf

Q: What is a heart rate?
A: The average number of heart beats per minute; a heart beat is when the heart contracts to pump blood thru your system.

Q: What is a resting heart rate?
A: Resting heart rate is the number of beats in one minute while you are at a complete rest state. Your resting heart rate indicates your basic overall heart health and fitness level. The more conditioned your body is, the less effort it needs to make to pump blood thru your body.

Q: What is a recovery heart rate?
A: This is the heart rate your body will drop to after two minutes, after stopping an exercise session. For instance you exercised for 30 minutes and your heart rate was at 155. Two minutes after you stopped exercising, your heart rate then decreased to 95. This recovery heart rate measure helps to evaluate your overall heart fitness level. Use this measurement to compare between exercise sessions

Q: What is a maximum heart rate?
A: A maximum heart rate (Max HR) is the highest number of beats your heart contracts during a one minute measurement. Max HR is a useful tool to measure training intensities and typically is used to measure or predict the level of exercise. It's always good to measure your Max HR while doing exercises to ensure you stay within a safe range or use it to measure if the exercise is actually working well enough to raise your heart rate to acceptable ranges and levels.

Q: How do I measure a Max HR?
A: The best method of determining your individual maximum heart rate is to be clinically tested and monitored on a treadmill. This is called a treadmill stress testing and is done by a cardiologist or certified physical therapist. Based on your age and physical condition, a formula is used to predict your Max HR. The other method is by using an age-predicted maximum heart rate formula:

WOMEN: 226 - your age = age-adjusted Max HR
MEN: 220 - your age = age-adjusted Max HR

Example: If you are a 30-year-old woman, your age-adjusted maximum heart rate is 226- 30 years = 196 bpm (beats per minute).

*note that this formula allows you to estimate your Max HR. Be sure to consult with your exercise trainer and doctors for the most effective rates that are customized to your health.

Heart Rate Charts:
Heart Rate Chart: Babies to Adults
AGE Beats Per Minute (BPM)
Babies to Age 1 100 - 160
Children ages 1-10 60 - 140
Children age 10+ and adults 60 - 100
Athletes: 40 - 60

Taken from: http://www.heart.com/heart-rate-chart.html

A sphere is a three-dimensional circle. Or you could say that a sphere is the set of all the points that are at the same distance from the center of the sphere. In nature, centrifugal force and gravity tend to make a lot of things into spheres: soap bubbles, for instance, atoms, and planets.

The radius of a sphere is the distance from its center to any point on its surface. The surface area of a sphere is the set of all the points on the outside of the sphere. To figure out what the surface area of a sphere is, you multiply the radius by itself and then multiply that by pi, so the formula is 4πr2. This is because the area is the length times the width (just like the area of a square). The width of a sphere is its diameter (twice the radius, or 2r). The length of a sphere is its circumference (2πr). So the width times the length, or the area, is 2r times 2πr, or 4πr2.

To figure out the volume of a sphere (how much air or water it would take to fill it up), you multiply the radius by itself and then by itself again, and then by pi, and then by 4, and divide the whole thing by 3. So the formula for the volume of a sphere is 4πr3/3.

Source: http://www.historyforkids.org/scienceforkids/math/geometry/sphere.htm