Given, Earth's diameter is approximately 12,760,000 meters.
This number in scientific notation will be 1.276 × 10⁷
Answer:
9 mph = the speed in still water
Step-by-step explanation:
Let r = the speed in still water
Then the speed going down stream is r + 3
and the speed going upstream is r - 3
d = rt or t = d/r
time going downstream is 16/(r + 3) and time going upstream is 16/(r - 3)
The total time was 4 hours, so
Multiply thru the equation by (r + 3)(r - 3)
Then 16(r - 3) + 16(r + 3) = 4(r + 3)(r - 3)
16r - 48 + 16r + 48 =
- 36
- 36 = 32r
- 32r - 36 = 0

4(r - 9)(r + 1) = 0
r = 9 or -1
But a rate of speed cannot be negative, so x ≠ -1
So, r = 9 mph = the speed in still water
Answer:
Option D
Step-by-step explanation:
By using geometric mean theorem in the given right triangle ABC,

BD² = AD × DC
h² = (AC - CD) × DC
h² = (25 - 16) × 16
h² = 9 × 16
h = 
h = 12
Therefore, measure of side h = 12 units.
Option D will be the correct option.
Answer:
1 hour
Step-by-step explanation:
I find these easiest to work by considering the initial difference in distance and the speed at with that gap is closing.
__
The gap is 15 miles, the distance the first ship is from harbor when the second ship starts.
The rate of closure is the difference in the speeds of the two ships:
60 mph -45 mph = 15 mph
Then the closure time is ...
time = distance/speed
time = (15 mi)/(15 mi/h) = 1 h
It will take the second ship 1 hour to catch up to the first ship.
Answer:
88 25/27
Step-by-step explanation:
(13 – 6)^2 (5 + 2)^2÷(5 – 2)^3
PEMDAS
Parentheses first
(7)^2 (7)^2÷(3)^3
Then exponents
49*49 ÷27
Then multiply and divide from left to right
2401÷27
2401/27
88 25/27
88.92592593