Answer:
A)
15 hours
B)
108 hours
C)
2074.29 miles
Step-by-step explanation:
Under the assumption the earth is a perfect circle, then in one complete rotation about its axis ( 24 hours) the Earth will cover 360 degrees or 2π radians.
A)
In every 24 hours the earth rotates through 360 degrees ( a complete rotation). We are required to determine the length of time it will take the Earth to rotate through 225 degrees. Let x be the duration it takes the earth to rotate through 225 degrees, then the following proportions hold;
(24/360) = (x/225)
solving for x;
x = (24/360) * 225 = 15 hours
B)
In 24 hours the earth rotates through an angle of 2π radians (a complete rotation) . We are required to determine the length of time it will take the Earth to rotate through 9π radians. Let x be the duration it takes the earth to rotate through 9π radians, then the following proportions hold;
(24/2π radians) = (x/9π radians)
Solving for x;
x = (24/2π radians)*9π radians = 108 hours
C)
If the diameter of the earth is 7920 miles, then in a day or 24 hours a point on the equator will rotate through a distance equal to the circumference of the Earth. Using the formula for the circumference of a circle;
circumference = 2*π*R = π*D
= 7920*3.142
= 24891.43 miles
Therefore a point on the equator covers a distance of 24891.43 miles in 24 hours. This will imply that the speed of the earth is approximately;
(24891.43miles)/(24 hours) = 1037.14 miles/hr
The distance covered by the point in 2 hours will thus be;
1037.14 * 2 = 2074.29 miles
Answer:
6.75 round to 7
Step-by-step explanation:
Answer:
Number of pineapples= 10
number of pears = 19
number of kiwis = 10 -2 = 8
Step-by-step explanation:
Cost of a pear = $ 0.50
Cost of a pineapple = $ 1.5
cost of a kiwi = $ 0.3
Let the pineapples = p
Number of pears = 9 + p
Number of kiwis = p - 2
The cost is
0.15 p + 0.5 (9 + p) + 0.3 (p - 2) = 13.50
0.15 p + 4.5 + 0.5p + 0.3 p - 0.6 = 13.50
0.95 p = 9.6
p = 10
I believe it’s the first one. 1.5 + 2 = 3.5
