in this system, potential and kinetic energy are ____ proportional.

Explanation:

Hi,

The answer is friction.

There is almost no machine which are not affected by friction. It losts some work due to friction while working.

Hope it helps..

Answer:

friction

Explanation:

the other options dont effect efficiency

Answer:

30°

Explanation:

The angle between the normal and the vertical is the same as the angle between the incline and the horizontal.  We can show this with geometry.

Answer:

1

Explanation:

Hydrogen is the first element in the periodic table so its atomic number is 1.

Answer:

When we have irregular objects, it may become very hard to calculate the volume of the object, as we actually can not use any simple equation to find it.

The mass is less tricky, just find a scale and wheight it, now we know the mass of the irregular object.

One way to measure the volume of the object is using water... how we do it?

Get some recipient with water, measure the height of the water.

Introduce your object into the water and totally submerge it, now the level of the water will rise. This is because as you introduce the object under the water, you are displacing up a given volume of water that has the same volume as the irregular object.

Now that you know the height of the water before and after you put your object, you can easily calculate the volume of water displaced, and that will be the volume of the object (the tricky part may be totally submerging the object if, for example, is wood and it floats, here you can use a thin wire to push it down but it will affect a little bit the measures.)

Answer:

$876.96

Explanation:

The energy used is:

3500 W × (24 hr/day) × (120 day) × (1 kW / 1000 W) = 10,080 kWh.

So the cost is:

10,080 kWh × ($0.087 / kWh) = $876.96

Answer:

D

Explanation:

The answer is D because:

A) Only doctors are allowed to prescribe medications.

B) Rita is not a chef/cook.

C) Rita is not a personal trainer

D) The job of a dietican is to provide reccomendations to their clients in order for them to implement a healthy lifestyle via consuming what is best for them.

Hope this helps :)

Answer:

D.) Making recommendations for healthy eating habits

Explanation: PLATO :)))

Answer:

Emphasizes

Explanation:

The expression of an art is intelligible to those that understand it, as such to make an impression an artist has to emphasize the point they want to communicate

An art is an expression of the personal experiences of the artist or a reaction to events or to reveal the realities as seen by the artist such as global warming and the environment, so as to get the attention of people with the goal to change them, such that a good art changes the most people, hence the need for emphasis.

Answer:

A - emphasizes

Answer:

The spring was compressed the following amount:

[tex]\Delta x=\sqrt{ \frac{m_1\,v_1^2+ m_2\,v_2^2}{k} }[/tex]

Explanation:

Use conservation of energy between initial and final state, considering that the surface id frictionless, and there is no loss in thermal energy due to friction. the total initial energy is the potential energy of the compressed spring (by an amount [tex]\Delta x[/tex]), and the total final energy is the addition of the kinetic energies of both masses:

[tex]E_i=\frac{1}{2} k\,(\Delta x)^2\\\\E_f=\frac{1}{2} m_1\,v_1^2+\frac{1}{2} m_2\,v_2^2[/tex]

[tex]E_i=E_f\\[/tex]

[tex]\frac{1}{2} k\,(\Delta x)^2=\frac{1}{2} m_1\,v_1^2+\frac{1}{2} m_2\,v_2^2\\k\,(\Delta x)^2=m_1\,v_1^2+ m_2\,v_2^2\\(\Delta x)^2=\frac{m_1\,v_1^2+ m_2\,v_2^2}{k} \\\Delta x=\sqrt{ \frac{m_1\,v_1^2+ m_2\,v_2^2}{k} }[/tex]

Answer:

The atom is mostly empty space.

Explanation:

Ernest Rutherford in the year 1911 developed a model of an atom. In his model the atom was shown that the atom is mostly empty spaces composed of negative electrons which orbits round a positive nucleus just like planets revolving round the sun.

Rutherford came up with this model by performing experiments in 1909 which involves the scattering of alpha particles on a thin gold foil. From this experiments he came up with his model.

Answer:

A!

Explanation:

The atom is mostly empty space.

Answer:

6.0×10⁻²¹ J

Explanation:

KE = 3/2 kT,

where KE is average kinetic energy per molecule,

k is the Boltzmann constant,

and T is absolute temperature.

KE = 3/2 (1.38×10⁻²³ J/K) (18 + 273.15) K

KE = 6.0×10⁻²¹ J

Answer:

The answer is 6.0×10⁻²¹ J , because KE = 3/2 kT,  where KE is average kinetic energy per molecule,  k is the Boltzmann constant,  and T is the absolute temperature.

KE = 3/2 (1.38×10⁻²³ J/K) (18 + 273.15) K

KE = 6.0×10⁻²¹ J

Answer:

C. Heat flows from lemonade to the ice

Explanation:

Transfer of heat from the drink to the ice is what melts the ice and cools the drink.

Answer:

D. 288 psig

Explanation:

The storage cylinder of recovered R-404A is a mixture of R-125, R-143 and R-134. The refrigeration sector has low temperatures for installation. The pressure of cylinder at 80 F will be 288 psig. The pure refrigerants have inside a container have saturation temperature which is equal to ambient temperature.

Answer:

230 = x + 105

x= 125

Explanation:

v = v0 + at

Answer:

C. Walk four times per week

Explanation:

If she wants to increase her time then, she has to walk four times per week.

The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object. The unit of speed is a meter/second. The generally considered unit for speed is a meter per second.

The mathematical expression for speed is given by

speed = total distance /Total time

As given in the problem Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She must walk four times a week if she wants to extend her time.

Thus, the correct answer is option C.

Learn more about speed from here, refer to the link;

brainly.com/question/7359669

#SPJ2

The question is incomplete, the complete question is,

Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She wants to increase her time. What should she do?

A. Walk at 4.5 miles per hour.

B. Walk for 50 minutes.

C. Walk four times per week.

D. Walk up and down more hills.

Answer:

17) a) 30 kg·m/s

b) 30 kg·m/s

c) 0.3 m/s.

18) 2.4 m/s

19) 360,000 N

The different make of  car is safer because the force acting on it  is 28,800 N, resulting much less impact

Explanation:

17) By conservation of linear momentum principle, we have;

m₁·v₁ + m₂·v₂ = m₁·v₁' + m₂·v₂'

Where;

m₁ = The mass of the astronaut = 100 kg

v₁ = The initial velocity of the astronaut = 0 m/s

m₂ = The mass of the equipment box = 2.5 kg

v₂ = The initial velocity of the equipment box = 0 m/s

v₁' = The final velocity of the astronaut

v₂' = The final velocity of the equipment box = 12 m/s

The final momentum of the equipment box = Mass of the equipment box × Final velocity

a) The final momentum of the equipment box = 2.5 kg × 12 m/s = 30 kg·m/s

b) Given that the box and the astronaut will move in opposite directions, we have;

m₁·0 + m₂·0 = -m₁·v₁' + m₂·v₂'

m₁·v₁' = m₂·v₂'

Therefore, the momentum of the astronaut will be equal to the momentum of the equipment box = 30 kg·m/s

c)  The velocity of the astronaut is given by th following relation;

100×0 + 2.5×0 = -100×v₁' + 2.5×12

100×v₁' = 2.5×12

v₁' = 2.5×12/100 = 30/100 = 0.3 m/s

The final velocity of the astronaut = 0.3 m/s.

18) By conservation of linear momentum principle, we have;

m₁·v₁ + m₂·v₂ = m₁·v₁' + m₂·v₂'

Where;

m₁ = The mass of the railway truck= 4000 kg

v₁ = The initial velocity of the railway truck= 8 m/s

m₂ = The mass of the stationary truck = 6000 kg

v₂ = The initial velocity of the stationary truck = 0 m/s

v₁' = The velocity of the two trucks immediately after collision

Therefore, we have;

4000 kg × 6 m/s + 6000 × 0 = (6000 + 4000) × v₁' = 10,000·v₁'

24,000 kg·m/s = 10,000·v₁'

v₁' = 24,000/10,000 = 2.4 m/s

The velocity of the two trucks immediately after collision is = 2.4 m/s

19) The change in kinetic energy of the car due to the collision = 1/2·m·(v₂² - v₁²)

The initial velocity of the car, v₁ = 12 m/s

The final velocity, v₂ = 0 m/s

The mass of the car, m= 600 kg

The time in which the car is brought to rest = 2 seconds

Initial time at point of collision, t₁ = 0 s

Time after collision, t₂ = 0.02 s

By Newton's second law of motion, we have

The force F acting on the car = Rate of change in momentum produced by the force

F = m × dv/dt

Force  = m × (v₂ - v₁)/(t₂ - t₁) = 600×(0-12)/(0.02 - 0) = -360,000 kg·m/s²

The force acting on the car  is equal and opposite to the force of the car =  360,000 N

b) For the different make of the car, we have;

m × (v₂ - v₁)/(t₂ - t₁) = 600×(0-12)/(0.25 - 0) = -28,800 kg·m/s². = -28,800 N

Therefore, the different make of  car is safer because the force acting on it  is 28,800 N, resulting much less impact.

Answer:

Explanation:

The speed of sound is very high . It is about 340 m /s . In one echo , it takes approximately

2 x 100 / 340

= .6 sec

In 10 simultaneous echo , it will take 6 s . It is difficult to measure .6 sec but to measure 6 s is easy and it can be made with greater precision , so we can calculate velocity of sound with great precision .

This is the reason why , instead of one echo , 10 echos are made and duration of 10 echo is measured , rather than making one echo and measuring time of one echo .  

Answer:

Train accaleration = 0.70 m/s^2

Explanation:

We have a pendulum (presumably simple in nature) in an accelerating train. As the train accelerates, the pendulum is going move in the opposite direction due to inertia. The force which causes this movement has the same accaleration as that of the train. This is the basis for the problem.

Start by setting up a free body diagram of all the forces in play: The gravitational force on the pendulum (mg), the force caused by the pendulum's inertial resistance to the train(F_i), and the resulting force of tension caused by the other two forces (F_r).

Next, set up your sum of forces equations/relationships. Note that the sum of vertical forces (y-direction) balance out and equal 0. While the horizontal forces add up to the total mass of the pendulum times it's accaleration; which, again, equals the train's accaleration.

After doing this, I would isolate the resulting force in the sum of vertical forces, substitute it into the horizontal force equation, and solve for the acceleration. The problem should reduce to show that the acceleration is proportional to the gravity times the tangent of the angle it makes.

I've attached my work, comment with any questions.

Side note: If you take this end result and solve for the angle, you'll see that no matter how fast the train accelerates, the pendulum will never reach a full 90°!

Answer:

D

Explanation:

because light has no space nor mass

Answer:

healthy diet

Explanation:

Exercise and a healthy diet are the two things people do to stay healthy

Answer:

The time she takes to reach the water from when she jumps off the platform is 1.71 s

Explanation:

According to the equations of motion, we have;

v = u - g·t

v² = u² - 2·g·s

s₁ = u₁·t₁ + 1/2·g₁·t₁²

The given parameters are;

The height of the platform (assumption: above the water) = 10 m

The velocity with which she jumps, u = 3 m/s

The acceleration due to gravity, g = 9.81 m/s²

The height to which she jumps, s, is found as follows;

v² = u² - 2·g·s

At maximum height, v = 0, which gives;

0 = 3² - 2×9.81×s

2×9.81×s = 3² = 9

s = 9/(2×9.81) = 0.4587 m

s = 0.4587 m

The time to maximum height, t, is found as follows;

v = u - g·t

0 = 3 - 9.81×t

9.81×t = 3

t = 3/9.81 = 0.3058 s

The total distance, s₁ from maximum height to the water surface = s + 10 = 0.4587 + 10 = 10.4587 m = 10.46 m

The time to reach the water from maximum height, t₁, is found as follows;

s₁ = u₁·t₁ + 1/2·g₁·t₁²

Where;

s₁ =  The total distance from maximum height to the water surface = 10.46 m

u₁ = The initial velocity, this time from the maximum height = 0 m/s

g₁ = The acceleration due to gravity, g (positive this time as the diver is accelerating down) = 9.81 m/s²

t₁ = The time to reach the water from maximum height

Substituting the values gives;

s₁ = u₁·t₁ + 1/2·g₁·t₁²

10.46 = 0·t₁ + 1/2·9.81·t₁²

t₁²= 10.46/(1/2×9.81) = 2.13 s²

t₁ = √2.13  = 1.46 s

Total time = t₁ + t = 1.46 + 0.3058 = 1.7066 ≈ 1.71 s.

Therefore, the time she takes to reach the water from when she jumps off the platform = 1.71 s.

Answer:

The tension in the rod as the ball moves through the bottom circle is 9.8 N

Explanation:

When the ball is released from rest, the centripetal force equals the weight of the ball. So mv²/r = mg where m = mass of ball = 0.5 kg, v = speed of ball, r = radius of vertical circle = length of rod = 0.5 m and g = acceleration due to gravity = 9.8 m/s²

v = √gr = √9.8 m/s² × 0.5 m = √4.9 = 2.21 m/s

Now at the bottom of the circle T - mg = mv²/r where T = tension in the rod

T = m(g + v²/r)

= m(g + (√gr)²/r)

= m(g+ gr/r)

= m(g + g)

= 2mg

= 2 × 0.5 kg × 9.8 m/s²

= 9.8 N

So, the tension in the rod as the ball moves through the bottom circle is 9.8 N

Answer:

The evaporation time gradually increased with the increase in surfactant concentration, i.e., from water to the concentration level of 0.005%. Furthermore, the evaporation time is significantly reduced, even lower than that of water containing relatively high concentrations from 0.01% to 0.1%.

your answer is...

C. potassium

Answer:CcCcccccc

Explanation:

Rfsgqh

Answer:

173psig

Explanation:

The storage cylinder of recovered R-410A is mixture of difluoromethane and pentafluoroethane which is used as a refrigerant in air conditioning application. The refrigeration sector has low temperatures for installation. The pressure of cylinder at 80 F will be 173 psig. The pure refrigerants have inside a container have saturation temperature which is equal to ambient temperature.

A containment canister of recovered r-410a has an estimated pressure of 173psig.

The retrieved R-410A preservation container is a blend of difluoromethane and pentafluoroethane, that is used as a compressor in air conditioning systems.

Assembly conditions in the freezer industry are extremely low. At 80 degrees Fahrenheit, the cylinder pressure will be 173 pounds per square inch.

The specific heat capacity of pure refrigeration systems within a cylinder is the same as the room temperature.

Learn more:

https://brainly.com/question/5793747?referrer=searchResults

Answer:1860g

Explanation:The force would have to be greater than 1580g, which is when the student is pulling the sliding book with the spring scale

Answer;

7.238°

Explanation

From question we know that the grating has 1,970 grooves per centimeter, we can convert to from (cm) to (nm) for unit consistency

The slit separation is expressed below

d=1cm/1970

d=0.0005076

=5076nm

Then the angle (in degrees) that the red light of wavelength 640 nm appear in first order can be calculated using expression below

Sin(x)= mλ/d

Where λ= wavelength=640 nm

d=slit separation

Sin(x)= mλ/d

Sin(x)=(1×640)/5076

=0.126

sin-1(0.126)

X= 7.238°

Therefore,the angle (in degrees) that the red light of wavelength 640 nm appear in first order is 7.238°

Answer:

Solution

Given:

initial velocity (u)=0m/s (because an object

starts from the rest)

time (t)=3sec

diatance travelled(s)=14m(16-2=14)

acceleration (a)=?

Now,

According to the formula

s=ut+1/2at^2

or,14 =0×3+1/2×a×3^2

or, 14=0+a/2×9

or, 14=9a/2

or, 9a=28

or, a=28/9

or, a=3.1 m/s^2

Therefore, the acceleration of the object is 3.1m/s^2 ans.

Answer:

Parachutes

Explanation:

Your parachute allows you to descend more slowly because it lowers terminal velocity by increasing your air resistance. Most parachutes are designed to create a large amount of drag and allow you to land at a safe, low speed.

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Explanation:

2. Sum the torques about the fulcrum.

(450 N) (2 m) − (350 N) x = 0

x = 2.57 m

3. Sum the torques about the fulcrum.

(3600 N) (0.20 m) − F (0.90 m) = 0

F = 800 N

Mechanical advantage is the ratio between the load force and effort force.

MA = 3600 N / 800 N

MA = 4.5

Velocity ratio is the mechanical advantage divided by efficiency.  Assuming the lever is 100% efficient:

VR = 4.5 / 1

VR = 4.5

4. Mechanical advantage is the ratio between the load force and effort force.

MA = 900 N / 600 N

MA = 1.5

The velocity ratio is the distance moved by the effort divided by the distance moved by the load.  For a 3 pulley system, VR = 3.

Efficiency is mechanical advantage divided by velocity ratio.

e = 1.5 / 3

e = 0.50

5. Sum the torques about the fulcrum.

(-300 N) (0.10 m) + F (0.03 m) = 0

F = 1000 N