• Is infrared harmful to human body?

    Best answer: No. Infrared is safe, but one must be careful not to get too warm, as in direct sunlight on a hot day.
    Best answer: No. Infrared is safe, but one must be careful not to get too warm, as in direct sunlight on a hot day.
    9 answers · 3 days ago
  • If 'infinity' is for real, isn't it possible to go the other way, as in just 1 grain of our sand may contain millions of universe?

    I say all that while not sitting on a wheelchair drooling.
    I say all that while not sitting on a wheelchair drooling.
    7 answers · 22 hours ago
  • How deep could an ocean get without breaking any of the laws of physics of the known observed understood universe?

    Could there be an ocean hundreds of miles or even hundreds of thousands of miles deep or even a few light seconds deep?
    Could there be an ocean hundreds of miles or even hundreds of thousands of miles deep or even a few light seconds deep?
    7 answers · 4 days ago
  • Does kinetic energy start zero?

    6 answers · 15 hours ago
  • Why do people choose to use radio waves for cell phone information transferring,?

    Best answer: Radio waves disperse evenly over long distances. Infrared is blocked by walls. x-ray and gamma rays are destructive.
    Visible light is seen by our eyes, so we do not need a cellphone to decode it. Am I right??
    Best answer: Radio waves disperse evenly over long distances. Infrared is blocked by walls. x-ray and gamma rays are destructive.
    Visible light is seen by our eyes, so we do not need a cellphone to decode it. Am I right??
    9 answers · 3 days ago
  • If a fly collides head-on with a railway train, the fly changes direction and must momentarily be stationary. So does it stop the train?

    A fly flying towards a railway locomotive collides with its windscreen. Its direction of travel switches from one to the polar opposite. In changing its velocity from one state to the polar opposite it follows that for an instant it must have been stationary. Since the fly was in contact with the locomotive when... show more
    A fly flying towards a railway locomotive collides with its windscreen. Its direction of travel switches from one to the polar opposite. In changing its velocity from one state to the polar opposite it follows that for an instant it must have been stationary. Since the fly was in contact with the locomotive when its velocity changed, did it therefore cause the locomotive to momentarily stop in its tracks?
    7 answers · 3 days ago
  • What can I do to understand my physics professor better?

    I have a B I don't understand a word she says though. I have to go to other places to get the subject. If I could I wouldn't go to her class except to take tests and quizzes.
    I have a B I don't understand a word she says though. I have to go to other places to get the subject. If I could I wouldn't go to her class except to take tests and quizzes.
    9 answers · 5 days ago
  • What unwanted energy transfer happens in a door hinge?

    Best answer: Coverting kinetic energy into heat energy. Heat energy is most unwanted energy.
    Best answer: Coverting kinetic energy into heat energy. Heat energy is most unwanted energy.
    4 answers · 1 day ago
  • A ball thrown horizontally at 26 m/s travels a horizontal distance of 51 m before hitting the ground.?

    Best answer: So the QUESTION was "A ball is thrown HORIZONTALLY with a velocity of 26m/s. It travels a horizontal distance of 51 m before hitting the ground. ( statements of fact ). What is the height from which the ball is thrown? (the missing question). Neglect air resistance( statement of limiting conditions). ... show more
    Best answer: So the QUESTION was "A ball is thrown HORIZONTALLY with a velocity of 26m/s. It travels a horizontal distance of 51 m before hitting the ground. ( statements of fact ). What is the height from which the ball is thrown? (the missing question). Neglect air resistance( statement of limiting conditions). Use g = 9.8 m/s^2 ( gravity varies so this sets the values for your location) "

    Time of flight = d/v
    = 51/26 s

    Vertically the motion is h = 1/2 g t^2
    = 1/2 * 9.8 * ( 51 / 26 )^2 = 18.9 m
    4 answers · 2 days ago
  • In physics, does -200 C have lower energy than 25 C, but -200 C is far more harmful than 25 C to human body?

    Best answer: The amount of energy held in the material is NOT what causes the problem. It is the CHANGE in energy in the human that counts. Consider a vehicle moving at 100km/hr. It hits a stationary truck. The truck has no energy but the original vehicle loses ALL of its energy. Now compare it with the moving vehicle hitting... show more
    Best answer: The amount of energy held in the material is NOT what causes the problem.
    It is the CHANGE in energy in the human that counts.
    Consider a vehicle moving at 100km/hr. It hits a stationary truck.
    The truck has no energy but the original vehicle loses ALL of its energy.
    Now compare it with the moving vehicle hitting a car moving in the same direction with some speed.
    There is more total energy but the vehicle loses less in the collision. The CHANGE is smaller.
    So if you take a human at 37 C interacting with something at 25 then compare it with the human interacting with something at -200
    The second scenario makes a far bigger CHANGE to the human. So it also creates more harm accordingly.

    There is no way to compare this with the energy in a photon of radio waves however.
    The only thing that the photon can do, other than nothing, is to give its energy to something that it hits.
    So the radio wave ALWAYS gives less energy in an interaction than the visible light does.

    Now there are many other factors not addressed here. But following the principle that the lower the CHANGE in energy then the radio waves would be expected to be less hazardous to a human.
    4 answers · 2 days ago
  • Can water evaporate at room temperature?

    I poured water into a cup and drew a line at where I first initially poured it. It’s been 3 days and the water has gone down about 2-3cm below the line. I have not exposed the water in the cup to sunlight, nor has anyone or anything touched the cup. It is isolated by itself and the water is going down. Any theories... show more
    I poured water into a cup and drew a line at where I first initially poured it. It’s been 3 days and the water has gone down about 2-3cm below the line. I have not exposed the water in the cup to sunlight, nor has anyone or anything touched the cup. It is isolated by itself and the water is going down. Any theories as to why this may be? I thought water evaporated at 212°, not at room temperature. Thanks in advance!
    15 answers · 1 week ago
  • How would it change reality if e=mc3?

    9 answers · 6 days ago
  • How does the sun radiate the radio waves?

    Best answer: The same way the Sun radiates ALL electromagnetic radiation because of nuclear fusion in the core. There are 2 nuclear fusion processes going on on the Sun's core.
    Best answer: The same way the Sun radiates ALL electromagnetic radiation because of nuclear fusion in the core. There are 2 nuclear fusion processes going on on the Sun's core.
    6 answers · 5 days ago
  • Why is the earth round ?

    26 answers · 1 week ago
  • Which one has higher energy? The cell phone’s radio waves or the bulb’s visible light?

    Best answer: It's true that the energy in light radiations from the bulb (incandescent tungsten filament) is higher than the energy in radio waves from the cell phone. But, the method of physical interaction is different. When light falls on atoms in the body, it gets reflected based on the color pigments in the skin. There... show more
    Best answer: It's true that the energy in light radiations from the bulb (incandescent tungsten filament) is higher than the energy in radio waves from the cell phone.
    But, the method of physical interaction is different.
    When light falls on atoms in the body, it gets reflected based on the color pigments in the skin. There is no harm done here.
    When microwaves and high energy radio waves fall on the skin, there may be changes produced such as heating in the skin due to inter-molecular motion or there may be voltages produced. Radio waves are different from visible light EMR in this matter and so they cause harm while light waves do not cause harm.
    5 answers · 4 days ago
  • Where did the energy come from in order to work to be done?

    [Purely Theoretical] While climbing up the stairs, the floor does not actually do work on you since your feet remain stationary while in contact with the floor. However, work is done by your legs on the rest of your body. Where did the energy come from in order to work to be done?
    [Purely Theoretical] While climbing up the stairs, the floor does not actually do work on you since your feet remain stationary while in contact with the floor. However, work is done by your legs on the rest of your body. Where did the energy come from in order to work to be done?
    9 answers · 1 week ago