Please I really need help on these

Paul lifts a sack weighing 245 newtons vertically from the ground and places it on a platform at a height of 0.7 meters. If he t

d1i1m1o1n [39]

Answer:

B. 17.15 watts

Explanation:

Given that

Time = 10 seconds

height = distance = 0.7 meters

weight of sack = mg = F = 245 newtons

Power = work done/ time taken

Where work done = force × distance

Substituting the given parameters into the formula

Work done = 245 newton × 0.7 meters

Work done = 171.5 J

Recall,

Power = work done/time

Power = 171.5 J ÷ 10

Power = 17.15 watts

Hence the power expended is B. 17.15 watts

6 0

3 years ago

When you go camping, you burn wood. Are you contributing to air pollution?

Jet001 [13]

Yes because of the smoke you are creating in the air

3 0

3 years ago

A vessel that contains a gas has two pressure gauges attached to it. One contains liquid mercury, and the other an oil such as d

castortr0y [4]

Answer:

Pressure of the gas = 12669 (Pa) and height of the oil is 1,24 meters

Explanation:

First, we can use the following sketch for an easy understanding, in the attached image we can see the two pressure gauges the one with mercury to the right and the other one with oil to left. We have all the information needed in the mercury pressure gauge, so we can determine the pressure inside the vessel because the fluid is a gas it will have the same pressure distributed inside the vessel (P1).

Since P1 = Pgas, we can use the same formula, but this time we need to determine the height of the column of oil in the pressure gauge.

The result is that the height of the oil column is higher than the height of the one that uses mercury, this is due to the higher density of mercury compared to oil.

Note: the information given in the units of the fluids is not correct because the density is always expressed in units of (mass /volume)

4 0

3 years ago

We are sending a 30 Mbit file from source host A to destination host B. All links in the path between source and destination hav

Dmitrij [34]

Answer:

$t=1.5\times 10^{-4}\ s$

Explanation:

Given:

file size to be transmitted, $D=30\ Mb$

transmission rate of data, $\dot D=10\ Mb.s^{-1}$

propagation speed, $v=2\times 10^8\ m.s^{-1}$

distance of data transfer, $s=10000\ km=10^4\ m$

Now the delay in data transfer from source to destination for each 10 Mb:

$t'=\frac{s}{v}$

$t'=\frac{10^4}{2\times 10^8}$

$t'=5\times 10^{-5}\ s$

Now this time is taken for each 10 Mb of data transfer and we have 30 Mb to transfer:

So,

$t=3\times t'$

$t=3\times 5\times 10^{-5}$

$t=1.5\times 10^{-4}\ s$

3 0

3 years ago

Which pair of variables defines motion?

masha68 [24]

Answer: position (x) and time (t)

Explanation:

A body is said to be in motion when its position changes with time with respect to a stationary observer.

Following are the types of motion:

Uniform motion: When equal amount of distance is covered in equal intervals of time.

Non-Uniform motion: When unequal amount of distance is covered in equal intervals of time.

Motion can be of the following types as well:

Rectilinear motion: when object moves in a straight line.

Circular motion: when object moves in a curved path.

Periodic motion: when motion repeats itself in fixed intervals of time.

Thus, in order to define motion, only two variables are required: position and time. Measuring these variables can determine whether the object is in motion or not and the type of motion.

5 0

3 years ago

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