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goblinko [34]
3 years ago
12

If a child ran into the road 65 to 70 feet ahead of your vehicle, what is the highest speed from which you could stop with good

brakes before hitting him? 30 mph 50 mph 40 mph 20 mph
Physics
1 answer:
Vlad [161]3 years ago
3 0
Given:
Stopping distance range is d = (65, 70) ft.

The stopping distance, d, obeys this formula.
d = v²/(2μg)
where
v = speed of the vehicle
μ = 0.8, coefficient of static friction under good road conditions
g =  acceleration due to gravity, 32.2 ft/s²

Therefore
v = √(2*0.8*32.2*d) = 7.178√d

Test d = 65 ft.
v = 7.178√(65) = 57.87 ft/s = (57.87/88)*60 = 39.5 mph

Test d = 70 ft.
v = 7.178√(70) = 60.05 ft/s = 40.9 mph

To be safe, the lower speed of 39.5 mph is preferred.

Answer: 40 mph
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Planck find the correct curve for the specturm of light emitted by a hot object by vibrational energies of the atomic resonators were quantized.

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  • The energy density of a black body between λ and λ + dλ is the energy E=hc/λ of a mode times the density of states for photons, times the probability that the mode is occupied. 
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3 0
1 year ago
The launching velocity of a missile is 20.0 m/s, and it is shot at 53º above the horizontal. What is the vertical component of t
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Given that

Velocity of missile (v) = 20 m/s ,

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Determine ,   Vertical component  = v sin Θ

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According to Coulomb's law, if the separation between two particles of the same charge increases four times, the potential energ
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8 0
3 years ago
Did the bigbang violate the law of conservation of energy and matter?
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The conservation of matter and energy states that the total amount of mass and energy at one time is the same at any other time. Notice how time is a crucial part of this statement. To even talk about conservation laws, you have to have time.

The upshot is that the Big Bang did not break the conservation laws because time itself is part of the universe and started at the Big Bang and because the conservation laws need to have time in their statements.
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The ice skaters partner liftes her up a distance of 1 m work done or not work done
SOVA2 [1]

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