a.) the belief that stars and planets revolve around the earth
Explanation:
The geocentric model of stars and planets is the belief that stars and planets revolves around the earth.
The model places the earth at the center of the system.
- Geo - earth ; centric - center
- This was the original school of thought about the way the earth relates to other bodies in the universe.
- This model was replaced by the heliocentric universe in which stars are at the center and the planets revolves round them.
- The idea was put forward by Nicola Copernicus
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Neptune was named after the Roman god of the sea and it is the last known of the planets
Answer:
Because the wavelengths of macroscopic objects are too short for them to be detectable.
Explanation:
Wavelength of an object is given by de Broglie wavelength as:

Where, 'h' is Planck's constant, 'm' is mass of object and 'v' is its velocity.
So, for macroscopic objects, the mass is very large compared to microscopic objects. As we can observe from the above formula, there is an inverse relationship between the mass and wavelength of the object.
So, for vary larger masses, the wavelength would be too short and one will find it undetectable. Therefore, we don't observe wave properties in macroscopic objects.
Answer:
The average power provided by the tension in the cable pulling the lift is = 714 W
Explanation:
Given data
Mass = 71 kg
Change in height = 123 m
When the lift moves in upward direction then in that case kinetic energy is constant & only potential energy changes.
Change in potential energy Δ PE = m g (
)
Δ PE = 71 × 9.81 × 123
Δ PE = 85670.73 J
Time = 2 min = 120 sec
So average power is given by



Therefore the average power provided by the tension in the cable pulling the lift is = 714 W