Question 1(Multiple Choice Worth 5 points)

2 answers:

6 0

Well, to cover the whole bridge, is 6/6, or 1 whole

so hmmm $\bf \begin{array}{ccllll}
concrete&bridge\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
\frac{4}{5}&\frac{5}{6}\\\\
x&\frac{6}{6}
\end{array}\implies \cfrac{\frac{4}{5}}{x}=\cfrac{\frac{5}{6}}{\frac{6}{6}}\implies \cfrac{\frac{4}{5}}{\frac{x}{1}}=\cfrac{\frac{5}{6}}{\frac{6}{6}}$

$\bf \cfrac{4}{5}\cdot \cfrac{1}{x}=\cfrac{5}{6}\cdot \cfrac{6}{6}\implies \cfrac{4}{5x}=\cfrac{5}{6}\implies 4\cdot 6=5\cdot 5x\implies 24=25x
\\\\\\
\boxed{\cfrac{24}{25}}=x$

shtirl [24]3 years ago

3 0

Answer:

dasfasdfadf

Step-by-step explanation:

You might be interested in

A 140 kg camera is suspended by two wires over a 40 metre wide football field to get shots of the action from above. At one poin

Katen [24]

Answer:

Please red the answer below

Step-by-step explanation:

In order to determine the length of each cable you use the Newton second law for each component of the forces involved in the situation.

For the x component you have:

$T_1cos\theta_1-T_2cos\theta_2=0$ (1)

T1: tension of the first cable = 1500N

T2: tension of the second cable = 800N

θ1: angle between the horizontal and the first cable

θ2: angle between the horizontal and the first cable

For the y component you have:

$T_1sin\theta_1+T_2sin\theta_2-W=0$ (2)

W: weight of the camera = Mg = (140kg)(9.8m/s^2) = 1372N

You can squared both equations (1) and (2) and the sum the two equations:

$T_1^2cos^2\theta_1=T_2^2cos^2\theta_2\\\\T_1^2sin^2\theta_1=T_2^2sin^2\theta_2-2WT_2sin\theta_2+W^2$

Then, you sum the equations:

$T_1^2(cos^2\theta_1+sin^2\theta_1)=T_2^2(sin^2\theta_2+cos^2\theta_2)-2Wsin\theta_2+W^2$ (3)

Next, you use the following identity:

$sin^2\theta+cos^2\theta=1$

and you obtain in the equation (3):

$T_1^2=T_2^2-2WT_2sin\theta_2+W^2\\\\sin\theta_2=\frac{T_2^2-T_1^2+W^2}{2WT_2}=\frac{(800N)^2-(1500)^2+(1372N)^2}{2(800N)(1372N)}=0.066\\\\\theta_2=sin^{-1}0.066=27.23\°$

With this values you can calculate the value of the another angle, by using the equation (1):

$\theta_1=cos^{-1}(\frac{T_2cos(27.23\°)}{T_1})=cos^{-1}(\frac{(800N)(cos27.23\°)}{1500N})\\\\\theta_1=61.69\°$

Now, you can calculate the length of each cable by using the information about the width of the football field. You use the following trigonometric relation:

$l_1cos\theta_1=40-d\\\\l_2cos\theta_2=d\\\\$