If a hot air balloon has shown rising above the top of a hill, the top of the hill is considered as a reference point.
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Reference Point:</h2>
It is a point that is used to standardize a experiment. The reference point is a constant point.
In the given problem:
- The hot air balloon is rising above the top of the hill. Here, the hill is a standard point that has a fixed (constant) height.
- Some other reference points are the top of the Eifel Tower or a famous shop which a person use to denote a certain distance.
Therefore, "If a hot air balloon has shown rising above the top of a hill" the top of the hill is considered as a reference point.
Learn more about Reference Point:
brainly.com/question/1674904
Answer:
3100 m/s
Explanation:
The relationship between frequency and wavelength of a wave is given by the wave equation:

where
v is the speed of the wave
f is its frequency
is the wavelength
For the wave in this problem,
f = 15,500 Hz

Therefore, the wave speed is

Answer:
Electrostatic Force...or a non-contact force
Explanation:
Answer:
50
Explanation:
The mechanical advantage of a machine is given by

where
is the output force
is the input force
For the crowbar in this problem,
is the force in input applied by the worker
is the force that the machine must apply in output to overcome the resistance of the window and to open it
Substituting into the equation, we find

The correct choice is
B. sublimation, then condensation
Sublimation is the name of the process where a solid directly converts into gas on heating. on heating solid crystals of iodine directly change into gas. hence this is sublimation.
condensation is the process where gas is converted into liquid on cooling.
here iodine gas is being converted into droplets on reducing the temperature. hence this is condensation.