1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
andrew11 [14]
3 years ago
8

Which scenario involves kinetic energy transforming into potential energy? A. a book lying on a shelf B. a train traveling at a

constant speed C. a person drawing back the string of a bow and arrow D. a ball beginning to descend after being thrown upward
Physics
1 answer:
NeX [460]3 years ago
6 0
The answer is C.

The Kinetic energy which was exerted and experience pulling the string of a bow is kept as a potential energy at the end of the arrow in contact with the string. Once release from aim at stationary position the potential energy is again transformed.
You might be interested in
Waxing or waning moon?
Dennis_Churaev [7]

Answer:

waning gibbious

Explanation:

7 0
3 years ago
Steam is to be condensed on the shell side of a heat exchanger at 150 oF. Cooling water enters the tubes at 60 oF at a rate of 4
zalisa [80]

Answer:

a. 572Btu/s

b.0.1483Btu/s.R

Explanation:

a.Assume a steady state operation, KE and PE are both neglected and fluids properties are constant.

From table A-3E, the specific heat of water is c_p=1.0\ Btu/lbm.F, and the steam properties as, A-4E:

h_{fg}=1007.8Btu/lbm, s_{fg}=1.6529Btu/lbm.R

Using the energy balance for the system:

\dot E_{in}-\dot E_{out}=\bigtriangleup \dot E_{sys}=0\\\\\dot E_{in}=\dot E_{out}\\\\\dot Q_{in}+\dot m_{cw}h_1=\dot m_{cw}h_2\\\\\dot Q_{in}=\dot m_{cw}c_p(T_{out}-T_{in})\\\\\dot Q_{in}=44\times 1.0\times (73-60)=572\ Btu/s

Hence, the rate of heat transfer in the heat exchanger is 572Btu/s

b. Heat gained by the water is equal to the heat lost by the condensing steam.

-The rate of steam condensation is expressed as:

\dot m_{steam}=\frac{\dot Q}{h_{fg}}\\\\\dot m_{steam}=\frac{572}{1007.8}=0.5676lbm/s

Entropy generation in the heat exchanger could be defined using the entropy balance on the system:

\dot S_{in}-\dot S_{out}+\dot S_{gen}=\bigtriangleup \dot S_{sys}\\\\\dot m_1s_1+\dot m_3s_3-\dot m_2s_2-\dot m_4s_4+\dot S_{gen}=0\\\\\dot m_ws_1+\dot m_ss_3-\dot m_ws_2-\dot m_ss_4+\dot S_{gen}=0\\\\\dot S_{gen}=\dot m_w(s_2-s_1)+\dot m_s(s_4-s_3)\\\\\dot S_{gen}=\dot m c_p \ In(\frac{T_2}{T_1})-\dot m_ss_{fg}\\\\\\\dot S_{gen}=4.4\times 1.0\times \ In( {73+460)/(60+460)}-0.5676\times 1.6529\\\\=0.1483\ Btu/s.R

Hence,the rate of entropy generation in the heat exchanger. is 0.1483Btu/s.R

4 0
3 years ago
One of the factors that determines the ? of a capacitor is the frequency measured in hertz.
olchik [2.2K]

Answer:

The reactance of the capacitor

Explanation:

In an AC circuit containing different elements (capacitors, resistors and inductors), we cannot simply calculate the equivalent resistance of the circuit, so another quantity is used, which is called reactance.

For a capacitor, the reactance is given by:

X=\frac{1}{2 \pi f C}

where:

f is the frequency of the AC current in the circuit

C is the capacitance of the capacitor

The reactance has a similar meaning to that of the resistance for a DC current. In fact, we notice that:

- When f=0 (which means we are in regime of DC current, because the current never changes direction), the reactance is infinite. This is correct: in a DC circuit, the capacitor does not let current pass through it, so it like it has infinite resistance (=infinite reactance)

- When f tends to infinite, the reactance becomes zero: in such situation, the current in the circuit changes direction so quickly that the capacitor has no enough time to "block" the current in the circuit, so it like it has almost zero resistance (zero reactance).

4 0
3 years ago
Read 2 more answers
Sort the sentences based on whether they describe radio waves, visible light waves, or both.
valentina_108 [34]

The electromagnetic spectrum includes a continuous spectrum of wavelengths that include:

Radio waves, microwaves, infrared light, visible, ultraviolet, X-rays, gamma rays

The wavelength decreases from radio waves to gamma rays, whereas the energy increases along the same direction.

In the given example, radio waves have a lower energy and higher wavelength than visible light. The latter can be perceived by the human eye, whereas radio waves are not visible to the human eye.

1) They have colors = visible light

2) They can travel in a vacuum  = both

3) They have energy = both

4) They’re used to learn about  dust and gas clouds = radio waves

5) They’re used to find the  temperature of stars  = visible light

6)They’re invisible = radio waves

6 0
3 years ago
Two observers in different inertial reference frames moving relative to each other at nearly the speed of light see the same two
lions [1.4K]

Answer:

The correct answer is d Both the observer's are correct

Explanation:

We know by postulates of relativity that laws of physics are same in different inertial frames.

Thus for each of the frames they make observations related to their frames and since the observations are true for their individual frames they both are correct. But when we compare the two frames we need to use transformation equations to compare both the results.

3 0
3 years ago
Other questions:
  • In a container of negligible heat capacity, mix 6kg of ice at -40 ° C with 3kg of steam at 120 ° C, determine the equilibrium te
    5·1 answer
  • A car is traveling at 100 km/h. How many minutes will it take to cover a distance of 750 km?
    5·1 answer
  • Cecily is inflating one of her bicycle tyres with the pump below. When she pushes the plunger down, does the volume of the gas i
    14·1 answer
  • Robert pushes the box to the left at constant speed. In doing so, Robert does ______ work on the box. A. positive B. negative C.
    11·1 answer
  • How do we know that water dissolves glue?
    10·1 answer
  • A 1.80 kg snowball is fired from a cliff 9.10 m high. The snowball's initial velocity is 17.4 m/s, directed 44.0° above the hori
    15·1 answer
  • Calculate the number of molecules of hydrogen and carbon present in 4 g of methane​
    7·2 answers
  • A car accelerates from a standstill to 60 km/hr in 10 seconds. what is the cars acceleration ​
    8·1 answer
  • I WILL REPORT YOU IF YOU ANSWER WITH LINK!!! WILL GIVE BRAINLIEST
    11·1 answer
  • You are an astronomer and are making observations about a visible but faraway galaxy. Describe what evidence you could gather to
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!