Critical Responces
1. San Andreas Fault- Explain why there are more earthquakes in the west coast than there are in the East Coast. Explain why there are more earthquakes along the San Andreas Fault.
#1 The tectonic plates are located between the Northern and Pacific plates and that is why earthquake activity happens more often in the West coast versus the East Coast. A large percentage of earthquakes happen on the Pacific ring of fire and that is along the side of the Pacific Ocean. In San Francisco, there are large amounts of man-made landfills near water with loose, soggy soil. This causes more damage when an earthquake happens. The San Andreas Fault is the sliding boundary between the Pacific Plate and the North American Plate. Due to its location, earthquakes happen frequently on the fault. The plates slowly move past each other a few inches a year, and suddenly all the built-up strain breaks the rocks along the fault. The breaking rocks send out waves in all directions. Parts of these plates are on land and parts are offshore.
1. Find the mean, median, and mode of these 20 numbers 10 10 10 20 20 20 20 20 20 30 30 30 30 30 30 40 40 40 50 50. What percent is greater than the mean? What percent is lower than the median?
#2. The mean is the average of all numbers. Numbers should be added and divided by the total number of addends. Therefore, 10+10+10+20+20+20+20+20+20+30+30+30+30+30+30+40+40+40+50+50=550, divided by 20 gives a mean of 27.5. The median is the number that falls in the middle of all the numbers. In this set there are 20 numbers with two 30's in the middle. 30 and 30 divided by 2 is still 30 so 30 is the median. The mode is the number that appears most often. Here, 20 appears six times, and 30 appears six times. Because 20 and 30 both appear six times, they are both the mode. To determine the percent, I total the numbers greater than 27.5, divide by the total numbers in the set and multiply by 100. There are 11 numbers above the mean and 20. 11/20=0.55 or 55% greater than the mean. To get the percent lower than the median I add numbers below 30 and divide by total numbers then multiply by 100. 9 numbers are below the median. 9/20=0.45 or 45% that are lower than the median.
1. A car tries to stop in the middle of the road (know Newton's law) but why might it be harder to stop when the road is wet? Identify the force that caused the skid. A book falls when the car stops- what law is this and why did it happen?
#3 Inertia is the resistance of any physical object, where an object in motion will stay in motion. A moving car has inertia, and everything in it too. If a driver stops suddenly, loose objects in the car will continue moving their original speed because of their inertia. When a book is not restrained, it will keep going until it comes in contact with an outside force, such as a windshield or dashboard, which applies the unbalanced force that stops the book's inertia A car can stop suddenly because tires cause friction. Traction is necessary to steer the car. Tractions refers to the maximum amount of friction the tires can handle before sliding. If they're subjected to high levels of frictional force or if the surface they're driving on has a lower threshold (like rain or ice) they're most likely to lose traction. When the road is wet, the traction created by gravity and friction is reduced and requires less brake to stop the car to avoid skidding if braking too hard and fast.
1. Dividing 2.55 by .6. Write this in fraction form. Turn this into an equivalent fraction to where you have a whole number in the denominator, identify the 2process used. Solve the equation and then describe how this exemplified the algorithm of dividing with decimals.
When changing 2.55 and .6 into fractions with a whole number as the denominator, I know that 2.55 is the same as 255/100 and if I add a 0 to .6, it becomes .60 which is the same as 60/100. Now, I just divide 255/100 by 60/100. Starting with the denominator, 100 divided by 100 is 1, and 255/60 is just that over 1. Anything divided by 1 is itself. Next I divide 60 into 255, from that I get the answer of 4 and 15/60. Using the GCF of 15, I reduced 4 and 15/60 down to 4 and got ¼.
