Friction can be useful when you trying to stop a car, also it can be useful in energy losses, increase wear and tear and produces heat

9. An object which is in circular motion (moving along a circle) is said to be accelerating because it changes it's direction constantly even if it is moving with a constant speed. cuz acceleration is change in either magnitude or direction of an object with respect to time.
therefore, it's still acceleration as change in direction with time.
10. Average speed of an object can be calculated by dividing the total distance covered by an object by time taken to cover that distance.
i.e
it can be re- arranged to find the distance as :
11. speed = 20 m/s : conversion into km/h
distance covered : 4 km = 4000 m
time taken = 200 seconds
12. let's use the first equation of motion to find the acceleration :
<span>In order to calculate an average, we should sum all numbers and divide them by quantity.
Let’s work with qualifications first. Let’s say you got a 10 in 1 exam, then an 8 in 2 exams and a 4 in 2 exams. Your average will be:
= (10*1+8*2+4*2) / 5 = 6.8
If 6 is the minimum, you will pass.
There is another way to calculate this average: applying distributive property.
= 10*1/5+8*2/5+4*2/5 = 6.8
Remember you can convert the fractions into equivalent fractions: 1/5 = 20/100; 2/5 = 40/100
= 10*20/100+8*20/100+4*20/100 = 6.8
We actually don’t have the number of atoms of each mass… we have the percentage instead! So we need to learn this last method for atoms.
Let’s go back to our atoms problem:
73.71 % of atoms have a mass of 27.98 u
14.93 % of atoms have a mass of 28.98 u
11.36 % of atoms have a mass of 29.97 u
So let’s put that in the formula:
Average mass = 27.98 u*73.71 /100 + 28.98 u*14.93 /100 + 29.97u*11.36 /100
So what you have to know is that a percentage can be converted into a fraction, and you should work that fraction in order to find the average. We can make the calculus shorter putting 100 as the common denominator:
Average mass = (27.98 u*73.71 + 28.98 u*14.93 + 29.97u*11.36)/100
So actually we are taking the percentage as if it was the quantity, and 100 as if it was the total (the total of all percentages is always 100). Maybe we don’t have 100 atoms, but it will be the same proportion anyway, whatever number we have! And here it is the result:
Average mass = 28,36u
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The salmon can travel at a speed of 2894673763462m/s and slide into my microwave!
PS- Don't judge the salmon, JUST BECAUSE IT ISN'T ATHLETIC!!!!
Worst regards,
Vivian Carolina Gartea Chiz Demetreo Perez Sanfrasio Smith