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3 years ago

What is the first step in solving this system by elimination?

1 answer:

4 0

You want to try and get rid of one of the variables ( x or y) so you would multiply the second equation by 2 which would make the x variable -2x which then when added to the first equation would eliminate the x variable.

Answer: c. Multiply the second equation by 2.

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A Ferris Wheel 22.0m in diameter rotates once every 12.5s. What is the ratio of a persons apperenet weight to her real weight (a

AnnZ [28]

<span>Acceleration of a passenger is centripetal acceleration, since the Ferris wheel is assumed at uniform speed:
a = omega^2*r

omega and r in terms of given data:
omega = 2*Pi/T
r = d/2

Thus:
a = 2*Pi^2*d/T^2

What forces cause this acceleration for the passenger, at either top or bottom?

At top (acceleration is downward):
Weight (m*g): downward
Normal force (Ntop): upward

Thus Newton's 2nd law reads:
m*g - Ntop = m*a

At top (acceleration is upward):
Weight (m*g): downward
Normal force (Nbottom): upward

Thus Newton's 2nd law reads:
Nbottom - m*g = m*a

Solve for normal forces in both cases. Normal force is apparent weight, the weight that the passenger thinks is her weight when measuring by any method in the gondola reference frame:
Ntop = m*(g - a)
Nbottom = m*(g + a)

Substitute a:
Ntop = m*(g - 2*Pi^2*d/T^2)
Nbottom = m*(g + 2*Pi^2*d/T^2)

We are interested in the ratio of weight (gondola reference frame weight to weight when on the ground):
Ntop/(m*g) = m*(g - 2*Pi^2*d/T^2)/(m*g)
Nbottom/(m*g) = m*(g + 2*Pi^2*d/T^2)/(m*g)

Simplify:
Ntop/(m*g) = 1 - 2*Pi^2*d/(g*T^2)
Nbottom/(m*g) = 1 + 2*Pi^2*d/(g*T^2)

Data:
d:=22 m; T:=12.5 sec; g:=9.8 N/kg;

Results:
Ntop/(m*g) = 71.64%...she feels "light"
Nbottom/(m*g) = 128.4%...she feels "heavy"</span>

7 0

4 years ago

Read 2 more answers

Which list shows the runners in order by their completion times from fastest to slowest

gogolik [260]

Answer:

answer is D

Step-by-step explanation:

12+1/2=12.5 12+2/5=12.4

3 0

3 years ago

The dimensions of the tank are 50 cm by 32 cm by 20 cm. The tank is full of water and sand. The ratio of the volume of water to

Sauron [17]

Given:

Dimensions of a tank are 50 cm by 32 cm by 20 cm

The tank is full of water and sand

Ratio of volume of water to the volume of sand is 5:1

To find:

Volume of water in the tank in liters

Solution:

Without loss of generality, let,

Length of tank = 50 cm

Breadth of tank = 32 cm

Height of tank = 20 cm

Then, we have,

Total Volume of the tank = Length * Breadth * Height

$\Rightarrow$ Total Volume = 50*32*20 cc

$\Rightarrow$ Total Volume = 32000 cc

It is given that,

Volume of water : Volume of sand = 5:1

$\Rightarrow$ (Volume of water)/(Volume of sand) = 5/1

Cross multiplying, we have,

Volume of sand = (Volume of water)/5

It is also given that the tank is full of water and sand. This implies that,

Volume of water + Volume of sand = Total Volume

Using the value, we obtained, we get,

Volume of water + (Volume of water)/5 = Total Volume

$\Rightarrow$ (6 * Volume of water)/5 = Total Volume

Plugging in the value of total volume, we get,

$\Rightarrow$ (6 * Volume of water)/5 = 32000 cc

$\Rightarrow$ Volume of water = $\frac{32000*5}{6}$ cc

$\Rightarrow$ Volume of water $\approx$ 26,666.6667 cc

We know that,

1 cc = 0.001 liters

$\Rightarrow$ 26,666.6667 cc = (26666.6667 * 0.001) liters

$\Rightarrow$ 26,666.6667 cc $\approx$ 26.667 liters

Thus, Volume of water in the tank is approximately 26.667 liters

Final Answer:

Volume of water in the tank (in liters) is approximately 26.667 liters

4 0

3 years ago

PLEASE ANSWER I REALLY NEED HELP ON THIS TEST

marshall27 [118]

Answer:

Step-by-step explanation:

beacause if you try to multiple 4x7.5 divided by 2 try it

6 0

3 years ago

Plzz help me and don't give me a negative answer for points

LenaWriter [7]

1. No idea
2. Angle A
3. Line RT
4. NO, 4/2 = 2, 5/3 = Not 2
5.Asking someone else?
6. 6 ft.
7. 10.56, precisely
8. 90 degrees
9. 51 degrees
10. 24 ft.

4 0

3 years ago