In my Earth Science class, I just finished teaching about phases of the moon. Trying to predict the date of the 1st quarter or full moon requires you to know how many days each month has.
I thought it may be helpful to show two easy methods to memorize how many days each month of the year has.
Method number one is using the knuckles on your hand
Start with the knuckle closest to your thumb and this knuckle will be January and the space in between knuckles will represent February then March, April, May, June, July, then for August you can start on your next hand or start over September October, November, December
All of the Months on the Knuckle have 31 days.
They are January, March, May, July, August, October, December
The months in the space between knuckles have 30 days except for February which has 28 days.
Another method you can use to memorize the days is this poem.
30 days has September,
April, June, and November.
When short February's done
All the rest have thirty-one
I actually use the poem to remember September has 30 days and February has 28 days combined with my knuckles.
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
But how are balanced and unbalanced forces different?
Forces have a magnitude and a direction.
Balanced forces will cause no change in the speed of an object.
Balanced forces acting on an object in opposite directions and equal in strength, as shown in the arrows below, do not cause a change in the speed of a moving object.
Objects that are not moving will not start moving if acted on by balanced forces.
Remember Forces have a magnitude and a direction
Unbalanced forces are not equal, and they cause the motion of an object to change
When two unbalanced forces are exerted in opposite directions, their combined force is equal to the difference between the two forces.
The magnitude and direction of the net force affects the resulting motion
This combined force is exerted in the direction of the larger force
Let’s look at several examples
The forces acting on the red pool balls are equal. The downward force of gravity is equal to the resistance force of the pool table.
When the white ball strikes the red balls the forces are unbalanced and they move in the direction of the force.
The forces are balanced on the weights. The downward force of gravity is equal to the resistance force of the yellow rack. The weights do not move. The weight lifter exerts an unbalanced force upward and the weights move in that direction.
The forces on the tennis balls are equal. They are not moving. The tennis balls are struck by an unbalanced force and it causes them to move.
The resistance force of the car is balanced with the downward force of gravity. The car jack exerts an unbalanced force on the car and the car moves in the direction of the force.
The car is at rest and all forces are balanced. When the car strikes the car at rest then the forces are unbalanced and the car moves in the direction of the force.
Learn about an energy pyramid and how the transfer of energy is demonstrated. A trophic pyramid shows where most of the energy in an ecosystem can be found. Each level is called a trophic level and as you move up trophic levels 90% of the energy is lost.
What causes tides?. Tides are the rise and fall of sea levels caused by three items, the gravitational force of the Moon the Sun and the rotation of the earth. So let’s take a look and see how these three items cause tides.
Gravity is the force of attraction between two objects. Anything that has mass also has gravity. Objects with more mass have more gravity. Gravity also gets weaker with distance. So, the closer objects are to each other, the stronger their gravitational pull is. Although the moon is much smaller than the Sun the moon's gravity has a much more pronounced effect on the Earth's ocean because it is closer than the Sun.
On the side of the earth that's facing the moon, the pull of gravity causes oceans to bulge outward due to the gravitational pull of the moon.
On the other side of the earth away from the moon, the gravitational attraction of the moon is less because it is farther away. Here, inertia exceeds the gravitational force, and the water tries to keep going in a straight line, moving away from the Earth due to centrifugal force, also forming a bulge.
The Earth rotates on its axis so this bulge, which is called the tidal bulge. is constantly changing location. The tidal bulge changes as the moon revolve around the earth. Where the Bulge is bigger it's high tide, and where the bulge is smallest,it's low tide.
The tidal range is the height difference between high tide and low tide. The world's largest tidal range of 16.3 meters and occurs in the Bay of Fundy, in Canada.
Most places get two high tides and two low tides each day. If you are on the part of the Earth-facing the moon you are at high tide, 6 hours later you will be at low tide, 6 hours later you will be back at high tide, and then 6 hours later you are back at low tide, and finally after 6 more hours you are back at high tide.
Approximately twice a month around the new moon and full moon when
the Sun Moon and Earth form a line the tidal force is at
its maximum and the tidal range is at its maximum this is called Spring
Tides. When the moon is at first quarter or third quarter the Sun and Moon are
separated by 90 degrees and the solar tidal force cancels the moon's tidal
force and the tidal range is at its minimum and these tides are called neap tides.
Learn about an energy pyramid and how the transfer of energy is demonstrated. A trophic pyramid shows where most of the energy in an ecosystem can be found.
Each level is called a trophic level and as you move up trophic levels 90% of the energy is lost.
My dog is considered a mammal, however, so is a dolphin and an elephant.
In this short video, I answer the question, " what makes a mammal a mammal?
There are over 4000 different species of mammals.
Mammals have several common traits.
A backbone,
Mammals are endothermic,
A unique jaw shape,
Glands that allow mammals to sweat and feed their offspring milk.
How to find the GCF of 24 and 40.
I like to use a factor to find the GCF of 40 and 24.
The GCF is the largest number that divides evenly into two or more numbers.
After finding the prime numbers you just multiply the pairs of prime numbers.
