Answer:
3 km/h
Explanation:
Let's call the rowing speed in still water x, in km/h.
Rowing speed in upstream is: x - 2 km/h
Rowing speed in downstream is: x + 2 km/h
It took a crew 9 h 36 min ( = 9 3/5 = 48/5) to row 8 km upstream and back again. Therefore:
8/(x - 2) + 8/(x + 2) = 48/5 (notice that: time = distance/speed)
Multiplying by x² - 2², which is equivalent to (x-2)*(x+2)
8*(x+2) + 8*(x-2) = (48/5)*(x² - 4)
Dividing by 8
(x+2) + (x-2) = (6/5)*(x² - 4)
2*x = (6/5)*x² - 24/5
0 = (6/5)*x² - 2*x - 24/5
Using quadratic formula
A negative result has no sense, therefore the rowing speed in still water was 3 km/h
Answer:
The building is 61.19 m tall, approximately.
Explanation:
From the parabollic movement trayectory equation,
where H is the initial height of the ball and 
and 
the inital velocities in the vertical and horizontal direction, respectively; we have
.
In this case, the ball landed at the coordinates 
, so
.
Answer: The piezoelectric effect describes the property of certain solids to generate an electrical charge under mechanical stress. The actuating force modifies the microscopic structure of the body; dipoles are created between which a voltage builds up. And Their positive and negative charges complement each other creating two types of electricity: static electricity
Explanation:
Answer:
Daltons
Explanation:
The unit used to measure weighted average atomic mass is the Atomic Mass Unit (amu) which is also known as Daltons.
