Answer:0.69
Explanation:
Coefficient of kinetic friction=f/R=61.8/90=0.69
The answer is D.
I hope this helps.
Answer:
, it will sink
Explanation:
The density of an object is given by
where
m is the mass of the object
V is its volume
For the body in the problem, we have
m = 4 kg = 4000 g
Therefore, its density is
And the object will sink in water, because its density is larger than that of water, which is 
. (an object sinks when its density is larger than that of water, otherwise it floats).
The energy in electron volts of the photons that has the following frequencies is as follows:
- 620 THz = 2.564eV
- 3.10GHz = 1.28 × 10-⁵eV
- 46.0 MHz = 1.902 × 10-⁷eV
<h3>How to calculate energy?</h3>
The energy of a photon can be calculated using the following formula:
E = hf
Where;
- E = energy
- h = Planck's constant (6.626 × 10-³⁴ J/s)
- f = frequency
First, we convert the frequencies to hertz as follows;
- 620THz = 6.2 × 10¹⁴Hz
- 3.10GHz = 3.1 × 10⁹Hz
- 46.0MHz = 4.6 × 10⁷Hz
- E = 6.626 × 10-³⁴ × 6.2 × 10¹⁴ = 2.564eV
- E = 6.626 × 10-³⁴ × 3.1 × 10⁹ = 1.28 × 10-⁵eV
- E = 6.626 × 10-³⁴ × 4.6 × 10⁷ = 1.902 × 10-⁷eV
Learn more about energy of a photon at: brainly.com/question/2393994
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Answer:
option B) is correct
Explanation:
perception distance is the distance traveled by the vehicle when the driver perceive the hazard situation.
reaction distance is the distance traveled by the vehicle after seeing the hazard situation and reacting to it.
Braking Distance is the distance traveled by the vehicle after applying the brake.
so, the sum of Perception Distance + Reaction Distance + Braking Distance is called the total stopping distance
hence option B) is correct .
