Answer:
red shift, indicating that the universe is expanding
Explanation:
Doppler effect occurs when a source of a wave (e.g. light, or sound waves) moves relative to an observer; as a result of this relative motion, the wavelength of the wave appears lengthened/shortened to the observer. Two situations can occur:
- The source of the wave is moving towards the observer - in this case, the wavelength of the wave becomes shorter. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the blue-end of the spectrum (blue-shift)
- The source of the wave is moving away from the observer - in this case, the wavelength of the wave becomes longer. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the red-end of the spectrum (red-shift)
In our universe, we observe a red-shift for all the distant galaxies: this means that these galaxies are moving away from us, so this is an indication that the universe is expanding.
The answer should be D) Cold air because even though its true sound can travel through all types of matter, air which is a gas, can travel but it travels SLOWLY while sound travels quickly in SOLIDS.
<span>10 inches
You are at risk of serious injury if you sit less than 10 inches away from the steering wheel, because of the speed and force the airbag deploys at. This is also part of the reason why driving instructors now instruct you to hold the steering wheel from the lower parts, rather than the top, which can cause your thumbs to break if the air bag deploys.</span>
Answer:
correct answer is 1 and 3
Explanation:
In direct measurement with an instrument, the precision or absolute error of the instrument is given by its appreciation, in this case we see that the measurements have two decimal places, so the appreciation of the instrument must be 0.01 cm
Based on this appreciation, the valid measurements are 5.52 and 5.5.
the other two measurements have errors much higher than the assessment of the instrument, for which there must have been some errors in the measurement.
The correct answer is 1 and 3
Answer:
Option A
Explanation:
An Uninterruptible Power Supply abbreviated as UPS is used in case of the failure of the power mains or the input power in order to ensure uninterrupted power supply.
The Ac voltage is first converted to DC and then again inverted to the AC and is fed to the system.
Thus if the UPS malfunctions then in order to check the output using multimeter we use AC voltage setting because the UPS purely supplies AC power, even if the power is supplied from its internal battery then also it inverts the DC into AC and then supply.
