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2 years ago

PLSS HELP!!! THIS IS URGENT

Physics

1 answer:

Fed [463]2 years ago

3 0

Answer:

D. Sand carried by rivers flows over and weathers the rocks.

Explanation:

The sand in the river is move because of the flow of the river and as the sand moves it grinds on the rocks in the river. This starts a process know as abrasion, in other words it means that it wheathers(grinds) against the rocks.

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A spring of spring constant k is attached to a support at the bottom of a ramp that makes an angle θ with the horizontal. A bloc

Nikitich [7]

Answer:

$x=\frac {kd^{2}}{2(mgsin\theta +\mu_{k}mgcos\theta)}$

Explanation:

From the law of conservation of energy

Energy lost by the spring, W=Kinetic energy gained, KE+Potential energy gained, PE+Work done by friction, Fr

$0.5kd^{2}=0.5mv^{2}+mgLsin\theta+\mu_{k}mgcos\theta x$

$x(mgsin\theta+\mu_{k}mgcos\theta)=0.5kd^{2}$

$x=\frac {kd^{2}}{2(mgsin\theta +\mu_{k}mgcos\theta)}$

The required distance from A to B is $x=\frac {kd^{2}}{2(mgsin\theta +\mu_{k}mgcos\theta)}$

5 0

3 years ago

1 poir

djverab [1.8K]

Answer:

D) 735 J(oules)

Explanation:

Work is defined as force * distance

Force is defined as mass * acceleration

Given a mass of 15 kg and a gravitational acceleration of 9.8 m/s² since the box is being lifted up, the force being applied to the box is 15 kg * 9.8 m/s² = 147 N

Since the distance is 5 meters, the work done is 147 N * 5 m = 735 N/m = 735 J, making D the correct answer.

4 0

3 years ago

plsssssss i need help Which source of law is most like common law: statutes, case law, or administrative law? Explain

Lisa [10]

Answer:

The answer is "case law".

Explanation:

This law is not based on law, but on legislatures, statutes, or legislation, on judgments. Its also used as a different term with common law, which is the collection of precedents as well as power on a specific subject established in previous judicial decisions that are a part of Common law, which is also recognized as case law to establish by the court system based on legal case law.

7 0

2 years ago

A 600g toy train completes 10 laps of its circular track in 1 min 20s. If the radius of the track is 1.2 m, Find the centripetal

Lynna [10]

Wow ! This will take more than one step, and we'll need to be careful
not to trip over our shoe laces while we're stepping through the problem.

The centripetal acceleration of any object moving in a circle is

 (speed-squared) / (radius of the circle) .

Notice that we won't need to use the mass of the train.

We know the radius of the track. We don't know the trains speed yet,
but we do have enough information to figure it out. That's what we
need to do first.

Speed = (distance traveled) / (time to travel the distance).

Distance = 10 laps of the track. Well how far is that ? ? ?

1 lap = circumference of the track = (2π) x (radius) = 2.4π meters

10 laps = 24π meters.

Time = 1 minute 20 seconds = 80 seconds

The trains speed is (distance) / (time)

 = (24π meters) / (80 seconds)

 = 0.3 π meters/second .

NOW ... finally, we're ready to find the centripetal acceleration.

 (speed)² / (radius)

 = (0.3π m/s)² / (1.2 meters)

 = (0.09π m²/s²) / (1.2 meters)

 = (0.09π / 1.2) m/s²

 = 0.236 m/s² . (rounded)

If there's another part of the problem that wants you to find
the centripetal FORCE ...

Well, Force = (mass) · (acceleration) .

We know the mass, and we ( I ) just figured out the acceleration,
so you'll have no trouble calculating the centripetal force.

4 0

2 years ago

Alcohol of mass 33.2g and density 0.79kg/m³ or 790kg/m³ is mixed with water of 9g. What is the density of the resulting mixture?

KATRIN_1 [288]

Answer:

0.83 g/cm³

Explanation:

The volume of the alcohol is ...

(33.2 g)/(0.79 g/cm³) ≈ 42.0253 cm³

The density of water is about 1 g/cm³, so the volume of 9 g of it is ...

(9 g)/(1 g/cm³) = 9 cm³

The total volume is ...

42.0253 cm³ +9 cm³ = 51.0253 cm³

The total mass is ...

33.2 g + 9 g = 42.4 g

So, the resulting density is ...

(42.4 g)/(51.0253 cm³) ≈ 0.83 g/cm³

The resulting mixture has a density of about 0.83 g/cm³.

_____

Additional comment

Alcohol dissolves in water, so the total volume will be slightly less than 51.0253 cm³. The attached curve shows the result of mixing ethanol and water.

The weight of a mole of ethanol is about 46 g, of water, about 18.02 g. Then the mole fraction of alcohol is ...

(33.2/46)/(33.2/46 +9/18.02) ≈ 0.59

The volume of the mix is then estimated to be (-1.05 cc/mol)(1.221 mol), or about 1.28 cm³ less than the volume indicated above. That brings the density up to about 0.85 g/cm³.

We're not completely sure of the relevance of this calculation, since many of the applicable parameters are not specified. The point is that the density of the mix will probably be slightly more than the value calculated above. YMMV

3 0

2 years ago