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steposvetlana [31]
3 years ago
8

A car moves with a speed of 72 km/h for 15 minutes and then with a speed of 80 km/h for the next 12 minutes. The total distance

covered by the car is:
Physics
2 answers:
sukhopar [10]3 years ago
8 0

Answer:

The total distance covered by the car is 3,810.08 m

Explanation:

Given;

initial speed of the car, u = 72 km/hr = 20 m/s

initial time, t₁ = 15 minutes = 900 s

final speed of the car, v = 80 km/hr = 22.22 m/s

final time, t₂ = 12 minutes = 720 s

The acceleration of the car is given as;

a = \frac{v-u}{t_2 -t_1} \\\\a = \frac{22.22-20}{900-720}\\\\a = 0.0123 \ m/s^2

The total distance covered by the car is given as;

v² = u² + 2as

where;

s is the total distance covered by the car

22.22² = 20² + 2(0.0123)s

22.22²  - 20² = 2(0.0123)s

93.728 = 0.0246s

s = 93.728 / 0.0246

s = 3,810.08 m

Therefore, the total distance covered by the car is 3,810.08 m

stiv31 [10]3 years ago
8 0

Answer:

34 km

Explanation:

Remark

You are dealing with distance not direction. So you just figure out the two parts separately and add.

15 minutes

t = 15 minutes * 1 hour / 60 minutes = 0.25 hours.

r = 72 km / hr

d = 72 km / hr * 0.25 hours

d = 18 km

12 minutes

t = 12 minutes * 1 hour/ 60 minutes = 0.2 hours

r = 80 km/hour

d = 80 * 0.2 = 16 km

Total distance

d = d1 + d2

d = 18 + 16 = 34 km

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Angelina_Jolie [31]

Answer:

20 Hz, 20000 Hz

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Explanation:

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The maximum frequency that a human ear can hear is 20000 Hz.

v = Velocity of sound = 332 m/s

Wavelength is given by

\lambda=\dfrac{v}{f}\\\Rightarrow \lambda=\dfrac{332}{20}\\\Rightarrow \lambda=16.6\ \text{m}

The longest wavelength that can be heard by the human ear is 16.6 m

\lambda=\dfrac{332}{20000}\\\Rightarrow \lambda=0.0166\ \text{m}

The shortest wavelength that can be heard by the human ear is 0.0166 m.

3 0
3 years ago
is a persons DNA likely to be more similar to the DNA of his biological parents or to the DNA of one of his first cousins
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It is more likely to be similar to his/her parents because the get half of their genetic code from their mom and half from their dad.

4 0
3 years ago
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Please help me with questions 1, 2 and 3. <br> i need a step by step explanation
kifflom [539]

Answer:

1) d

2) 5 m/s

3) 100

Explanation:

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f=\frac{x(t_1)}{x(t_2)}=\frac{\frac{1}{2}at_1^2 }{\frac{1}{2}at_2^2}=\frac{t_1^2}{t_2^2}=\frac{10^2}{1^2}=\frac{100}{1}

5 0
3 years ago
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Evgesh-ka [11]

Answer:

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Where Ф = angular displacement of the object, t = time, ω' = initial angular velocity, α = angular acceleration.

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make α the subject of the equation

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Substitute into equation 3

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<h2>♨ANSWER♥</h2>

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