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Nataly_w [17]
1 year ago
7

A typical automobile under hard braking loses speed at a rate of about 7.2 m/s2; the typical reaction time to engage the brakes

is 0.55 s. A local school board sets the speed limit in a school zone such that all cars should be able to stop in 3.6 m. What maximum speed does this imply for a car in the school zone?
Physics
1 answer:
Korvikt [17]1 year ago
7 0

Answer:

4.3 m/s

Explanation:

a = rate at which the automobile loses speed = - 7.2 m/s²

v₀ = initial maximum speed of automobile

t' = reaction time for applying the brakes = 0.55 s

d = distance available for stopping the vehicle = 3.6 m

d' = distance traveled while applying the brakes = v₀ t' = (0.55) v₀

v = final speed after the vehicle comes to stop = 0 m/s

Using the equation

v² = v₀² + 2 a (d - d' )

0² =  v₀² + 2 (- 7.2) (3.6 -  (0.55) v₀)

v₀ = 4.3 m/s

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41.27m/s

Explanation:

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0.2(43.7)+0.0459(30.7) = (0.2+0.0459)v

8.74+1.409 = 0.2459v

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v = 41.27m/s

Hence the speed of the golf ball immediately after impact is 41.27m/s

8 0
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Bats use a process called echolocation to find their food. This involves giving out sound waves that hit possible prey or food.
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In Part 6.2.2, you will determine the wavelength of the laser by shining the laser beam on a "diffraction grating", a set of reg
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λ = 2042 nm

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we will find first angle between first max and central bright

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tan θ = 4.5 ×10^{-2}  / 11

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and we know diffraction grating for max

L sinθ  = mλ

here we know m = 1  so put all value and find λ

L sinθ  = mλ

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3 0
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When 30 V is applied across a resistor it generates 600 W of heat: what is the magnitude of its resistance?
grandymaker [24]

Answer:

<h2>1.5 ohms</h2>

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