The solution would be like this for this specific problem:
Volume of a cylinder = pi * r^2 * h
Volume of a cone = 1/3 * pi * r^2 * h
Total Height = 47
Height of the cone = 12
Height of the cylinder = 35
If the top half is filled with sand, then:
volume (sand) = pi * 4^2 * 36
volume (cone) = 1/3 * pi * 4^2 * 12
Total volume = 1960.353816 cubic millimeters
353816 / (10 * pi) = 62.4 seconds.
It will take 62.4 seconds until all of the sand has dripped to the bottom of the hourglass.
Answer:

Step-by-step explanation:
Given
sinΘ =
= 
Then the hypotenuse = 5 and one leg of the right triangle is 3
Using Pythagoras' identity to find the second leg (x)
x² + 3² = 5²
x² + 9 = 25 ( subtract 9 from both sides )
x² = 16 ⇒ x = 4
cosΘ =
= 
Answer:
The time taken by object to travel 21 ft is 1 sec
Step-by-step explanation:
The distance travel by falling object given as
d = 5 t + 16 t²
The Distance cover by object to travel = 21 ft
so , from Distance time equation
21 = 5 t + 16 t²
or, 16 t² + 5 t - 21 = 0
Or, 16 t² - 16 t +21 t - 21 = 0
Or, 16 t ( t - 1) + 21 (t - 1) = 0
Or. (t - 1) (16 t + 21) = 0
Or, (t - 1) = 0 And (16 t + 21) = 0
∴ t = 1 And t = (
)
Hence The time taken by object to travel 21 ft is 1 sec Answer
Rachel bought a collection of buttons.
2/4 of the buttons are yellow. 2/4 * 8 = 1/2 * 8 = 4 yellow buttons
2/8 of the buttons are red. 2/8 * 8 = 1/4 * 8 = 2 red buttons
Therefore, because we know that 4 of the buttons are yellow and 2 of the buttons are red, and we know that 4 > 2, we know that more yellow buttons were bought.