48 POINTS

Your backpack has a mass of 8 kg. You lift it from the ground to a height of

motikmotik

Answer:

the answer will be 5.6 j..

hope you like the answer.....

3 0

3 years ago

A 3 inch fire hose has a water flow of 200 gallons per minute. What is the flow in liters per second? Note: Use US gallons not U

stepladder [879]

Answer:

Case I: 12.617 L/s

Case II: 161.406 cubic meters per hour

Case III: 1.062 Pound inches

Explanation:

<u>Given:</u>

Speed of water flow = 200 gallons per minute
Speed of air blow = 95 cubic feet per minute
Measure of Torque = 12 Newton centimeter

<u>Assumptions:</u>

1 US gallon = 3.785 L
1 min = 60 s
1 ft = 0.3048 m
1 h = 60 min
1 inch = 2.54 cm
1 N = 0.2248 lb

Case I:

$Speed\ of\ water\ flow = 200 \dfrac{gallon}{min}\\\Rightarrow V_{water} = 200\times \dfrac{3.785\ L}{60\ s}\\\Rightarrow V_{water} = 12.617\ L/s$

Case II:

$Speed\ of\ air\ blow = 95 \dfrac{ft^3}{min}\\\Rightarrow V_{air} = 95\times \dfrac{(0.3048\ m)^3}{\dfrac{1}{60}\ h}\\\Rightarrow V_{air} = 95\times (0.3048)^3\times 60\ m^3/h\\\Rightarrow V_{air} = 161.406\ m^3/h$

Case III:

$Measure\ of\ torque = 12\ N cm\\\Rightarrow \tau = 12\times (0.2248\ lb)\times \dfrac{1}{2.54}\ in\\ \Rightarrow \tau = 1.062\ lb in$

6 0

3 years ago

Sharece knows that wave peaks and valleys can add and subtract. What would be the net effect if she was able to cross Wave 1 (a

levacccp [35]

Answer:

The two waves will add vectorially to produce a small amplitude wave in a valley phase.

Explanation:

The two waves will add vectorially to produce a small amplitude wave in a valley phase. This is because the amplitudes of the waves are slightly different and in opposite directions. When wave 1 cancels out all of wave 2, the resultant wave would be the slight difference between both waves, and it would be in the direction of wave 1 which is a valley phase.

6 0

3 years ago

If 128 g of material is in the shape of a brick 2 cm wide, 4 cm high, and 8 cm long, what is the density of the material?

Nastasia [14]

Answer:

2000 kg/m³

Explanation:

Density = (mass[kg])/(volume[m³])

Density of the brick = (.128kg)/(.02•.04•.08) = 2000 kg/m³

3 0

3 years ago

Imagine you are in an open field where two loudspeakers are set up and connected to the same amplifier so that they emit sound w

weeeeeb [17]

Question:

If you are 3.00 m from speaker A directly to your right and 3.50 m from speaker B directly to your left. What is the shortest distance d you need to walk forward to be at a point where you cannot hear the speakers?

Answer:

The shortest distance d you need to walk forward to be at a point where you cannot hear the speakers is 5.625 m

Explanation:

Shortest distance is given by

For constructive interference of wave, we have

$\Delta r_{construct}$ = 2nλ/2

For destructive interference of wave, we have

$\Delta r_{destruct}$ = (2n+1)λ/2

That is the difference in the number of wavelength between constructive and destructive interference is λ/2

We note that our positioning is 3.0 m from the first speaker and 3.5 m from the second, Which is of the form 2n and 2n + 1

Therefore when we walk forward away from the two speakers, we cannot hear the speakers at

Δr = λ/2 = r $_B$ - r $_A$

Which is the distance between the points where we have constructive and destructive interference or where there is destructive interference between the waves

Where:

r $_A$ = Distance from speaker A and

r $_B$ = Distance from speaker B

λ/2 = (344 m/s /688 Hz)/2

= 1/4

For

λ/2 = r $_B$ - r $_A$ we have

√(3.5² +d²) - √(3²+d²) = 1/4

∴ d = 5.625 m

6 0

3 years ago