Easy queation from 07

[oliver.shen2005]

27) Megan has [unparseable or potentially dangerous latex formula] coin, she has three times as many dimes as quarters, six times as many pennies as nickels and the total value is $[unparseable or potentially dangerous latex formula]. How many dimes does she have?
38) Three bowling balls are pushed together on the floor and a fourth is stacked on top. If bowling balls are [unparseable or potentially dangerous latex formula] inches in diameter, what is the vertical distance from the floor to the top of the fourth bowling ball?

[AuSmith]

27) [unparseable or potentially dangerous latex formula]

[unparseable or potentially dangerous latex formula]

[unparseable or potentially dangerous latex formula]

[unparseable or potentially dangerous latex formula]


Sub and solve. [unparseable or potentially dangerous latex formula] and [unparseable or potentially dangerous latex formula] becomes

[unparseable or potentially dangerous latex formula]

[unparseable or potentially dangerous latex formula]

and

[unparseable or potentially dangerous latex formula]

[unparseable or potentially dangerous latex formula]

and

[unparseable or potentially dangerous latex formula]

[unparseable or potentially dangerous latex formula]

and

[unparseable or potentially dangerous latex formula]

or

[unparseable or potentially dangerous latex formula]

from which

[unparseable or potentially dangerous latex formula].

Thankfully, [unparseable or potentially dangerous latex formula].

38) You know the centers of the balls on the bottom are [unparseable or potentially dangerous latex formula] inches high, and the center of the top ball is [unparseable or potentially dangerous latex formula] inches from the top. Then connect the four centers of the balls into a pyramid with equilateral triangle faces (regular tetrahedron) and side lengths of [unparseable or potentially dangerous latex formula] in. We only want to find the height of this pyramid, then add [unparseable or potentially dangerous latex formula] to it. Let the diagram show the bottom triangle.

bowling ball prob.png (1.73 KiB) Viewed 1602 times

The foot of the altitude from the top vertex will land at the centroid of the bottom triangle. The altitude and the red line segment are the legs of a right triangle with hypotenuse [unparseable or potentially dangerous latex formula] in. We know the red line segment has length [unparseable or potentially dangerous latex formula] of the whole cevian (centroid property). So, the red segment is length

[unparseable or potentially dangerous latex formula]

so the height is

[unparseable or potentially dangerous latex formula]

final answer [unparseable or potentially dangerous latex formula]

[B3ndythumbs]

holla holla! I gots some questions too pleez!

27. What is the roaming area of a dog on a 30 ft leash if its tied to a fence with 6 ft wide opening 20 ft away?

28. An insect pest population doubles every 18 days. If an insecticide kills 90 percent of the insects, how often should it be applied to keep in insect pop. in check?

There was that problem with the cooling coffee cup on UIL D? I havent got my test back, but could someone explain how to make the model eq?

Also, for the kinematics problems, are there some derived formulas that make the calculations easier? I have to plug into my 4 x-direction and 4 y-direction equations and solve. takes forever?

[AuSmith]

27. You have two semicircles. [unparseable or potentially dangerous latex formula]

28. If you start with population [unparseable or potentially dangerous latex formula], we want to apply pesticide every [unparseable or potentially dangerous latex formula] days so that

[unparseable or potentially dangerous latex formula],

and so

[unparseable or potentially dangerous latex formula],

we want the exponent to be [unparseable or potentially dangerous latex formula],

[unparseable or potentially dangerous latex formula]