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3 years ago

Newton's Three Laws - Complete the sentences.

1 answer:

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1. The answer is <span>An object won't move by itself, and once in motion, it won't stop unless some force acts upon it.
2. The rate of change of momentum is directly related to the force pressed upon it. In other words, when an object is pushed with more force, it will move faster and further away.
<span>3. To every action, there is equal and opposite reaction. </span></span>

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create a formula giving the strength of the induced field (B) i terms of current (I) and the distance from the wire to the probe

iren [92.7K]

So we need to find the formula for magnetic field B using the current (I) and the distance from the probe (d). So, We know that the stronger the current I, the stronger the magnetic field B. That tells us that the I and B are proportional. Also we know that the strength of the magnetic field B is weaker as the distance d of the probe increases. That tells us that B and d are inversely proportional. So our formula should have B=(I/d)*c where c is a constant of proportionality. c=μ₀/2π where μ₀ is the permeability of free space. So finally our formula is B=(μ₀I)/(2πd).

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3 years ago

A 1000 kg elevator accelerates upward at 1.0 m/s2 for 10 m, starting from rest. a. How much work does gravity do on the elevator

Ivenika [448]

Here you go mate. Hope it helps u. Pls follow me in reddit lol username: RobloxNoob2006

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3 years ago

Mike is a runner. Mike runs 200m in 25s; what is his average velocity during the run? assume that units are in m/s. (asap, will

maw [93]

Velocity is displacement/time
(Displacement is the overall change in distance)

So you’ll want to divide 200 by 25, which should give you:

8 m/s

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4 years ago

Steam is leaving a pressure cooker whose operating pressure is 20 psia. It is observed that the amount of liquid in the cooker h

Debora [2.8K]

Answer:

a) 34.05ft/s

b).1156.2BTU/lbm

c) 2.04BTU/s

Explanation:

Amount of liquid that has evaporated, m = ◇Vliq/ Vf

We replace the values to make conversion

m = (0.6gal/ 0.01683ft^3/lbm) × (0.13368ft^3/1gal)

m = 4.755lb

The mass flow rate of exit steam is given by:

m' = m/◇t

We replace values to make conversion

m' =( 4.766lb/45min) = 0.1059lb/min × 1min/60s

m' = 0.001765lb/s

The exit velocity V = m'/pA = m'Vg/A

We replace values to make conversion

V =[ (0.001765lbm/s)(20.093ft^3/lbm) /(0.15 in^2)]× (144in^2/1ft^2)

V = 34.05ft/s

b) The total and flow energies per unit mass is given by:

Eflow= Pv = h - u

We replace the values to make conversion

Eflow = 1156.2 - 1081.8

Eflow = 74.4BTU/lbm

Therefore theta= h + ke + pe

Theta approximately =h = 1156.2BTU/lbs

c) The rate at which energy is leaving the cooler by steam is given by:

Emass = m'theta

Emass = (0.001765)×(1156.2)

Emass = 2.04BTU/s

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4 years ago

Consider a Carnot heat-engine cycle executed in a closed system using 0.025 kg of steam as the working fluid. It is known that t

ArbitrLikvidat [17]

Answer:

The temperature of the steam during the heat rejection process is 42.5°C

Explanation:

Given the data in the question;

the maximum temperature T $_H$ in the cycle is twice the minimum absolute temperature T $_L$ in the cycle

T $_H$ = 0.5T $_L$

now, we find the efficiency of the Carnot cycle engine

η $_{th$ = 1 - T $_L$ /T $_H$

η $_{th$ = 1 - T $_L$ /0.5T $_L$

η $_{th$ = 0.5

the efficiency of the Carnot heat engine can be expressed as;

η $_{th$ = 1 - W $_{net$ /Q $_H$

where W $_{net$ is net work done, Q $_H$ is is the heat supplied

we substitute

0.5 = 60 / Q $_H$

Q $_H$ = 60 / 0.5

Q $_H$ = 120 kJ

Now, we apply the first law of thermodynamics to the system

W $_{net$ = Q $_H$ - Q $_L$

60 = 120 - Q $_L$

Q $_L$ = 60 kJ

now, the amount of heat rejection per kg of steam is;

q $_L$ = Q $_L$ /m

we substitute

q $_L$ = 60/0.025

q $_L$ = 2400 kJ/kg

which means for 1 kilogram of conversion of saturated vapor to saturated liquid , it takes 2400 kJ/kg of heat ( enthalpy of vaporization)

q $_L$ = h $_{fg$ = 2400 kJ/kg

now, at h $_{fg$ = 2400 kJ/kg from saturated water tables;

T $_L$ = 40 + ( 45 - 40 ) ( $\frac{2400-2406.0}{2394.0-2406.0}\\}$ )

T $_L$ = 40 + (5) × (0.5)

T $_L$ = 40 + 2.5

T $_L$ = 42.5°C

Therefore, The temperature of the steam during the heat rejection process is 42.5°C

4 0

3 years ago