What is this question supposed to be?
Answer:
1. Precise
2.Both
3.Precise
5.Neither
Step-by-step explanation:
Accuracy is the closeness of a measured value to a standard value.
Precision is the closeness of two or more measurements to each other.
1.The norm is 45 sit-ups in a minute.The students did, 64, 69,65 and 67. Values are not accurate compared to standard value 45.
Values are precise
Answer--Precise
2. Average score is 89.5
Scores are 89,93,91,87
Values are precise i.e a difference of 2 from each score
Values are accurate because the average score is 90 thus compared to the known average score of 89.5 they are accurate.
Answer-Both
3. Yesterday temperature=89
Tomorrow=88
Next day=90
Average =75
Values are precise i.e. difference of ± 1°
Values are not accurate compared to the average temperatures of 75 F
Answer---Precise
5. The jar contained 568 pennies
The 6 people guessed the numbers as
735,209,390,300,1005, 689
The values are not precise
The values are not accurate
Answer---Neither
Answer:
The kinetic energy is 20,000\ J
Step-by-step explanation:
The kinetic energy of a body is defined as:

Where <em>m</em> is the mass of the roller coaster car
<em>s</em> is the speed and <em>k</em> is the kinetic energy
We know that 

Then the kinetic energy of the roller coaster car is:

2x - 3y = 3.....multiply by 4
5x - 4y = 4....multiply by -3
--------------
8x - 12y = 12 (result of multiplying by 4)
-15x + 12y = -12 (result of multiplying by -3)
-------------
- 7x = 0
x = 0 <===
You take 94.5 and divide by 4.5 get 21