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2 years ago

15

Al llegar a detenerse, un automóvil deja marcas de derrape de 92m de largo sobre una autopista. Si se supone una desaceleración

de 7 m/s, estime la rapidez del automóvil justo antes de frenar

1 answer:

Bezzdna [24]2 years ago

8 0

Answer:

Explanation: no se español

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An object moving with a speed of 35M/s and has a kinetic energy of 1500 J what is the mass of the object

Lelu [443]

2.45 Kg

Explanation:

K.E = 0.5 mv^2

1500 = 0.5 × m × (35)^2

1500= m × 0.5 × 1225

1500 = m × 612.5

1500/612.5 = m

2.45 = m

m = 2.45kg

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2 years ago

A) The current theory of the structure of the Earth, called plate tectonics, tells us that the continents are in constant motion

suter [353]

A) The mass of the continent is $2.5\cdot 10^{21} kg$

B) The kinetic energy is 2016 J

C) The speed of the jogger should be 7.1 m/s

Explanation:

A)

The mass of the continent can be calculated as

$m = \rho V$

where

$\rho = 2800 kg/m^3$ is its density

V is its volume

We have to calculate its volume. We know that the continent is represented as a slab of side 5900 km (so its surface is 5900 x 5900, assuming it is a square) and depth of 26 km, so its volume is:

$V=(5900 km)^2 (26 km)=9.05\cdot 10^8 km^3 =9.05 \cdot 10^8 \cdot (10^9 m^3/k^3)=9.05\cdot 10^7 m^3$

So, the mass of the continent is

$m=\rho V = (2800)(9.05\cdot 10^{17})=2.5\cdot 10^{21} kg$

B)

The kinetic energy of a body is given by

$K=\frac{1}{2}mv^2$

where

m is the mass of the body

v is its speed

For the continent, we have:

$m=2.5\cdot 10^{21} kg$ is the mass

$v=4 cm/year$ is the speed

We have to convert the speed into SI units. we have:

1 cm = 0.01 m

$1 year = (365)(24)(60)(60) s = 3.15\cdot 10^7 s$

So, the speed is

$v=4 cm/year = 0.04 m/year \cdot \frac{1}{3.15\cdot 10^7}=1.27\cdot 10^{-9} m/s$

Therefore, the kinetic energy is

$K=\frac{1}{2}(2.5\cdot 10^{21} kg)(1.27\cdot 10^{-9} m/s)^2=2016 J$

C)

Again, the kinetic energy of an object is

$K=\frac{1}{2}mv^2$

For the jogger in this problem, his mass is

m = 80 kg

And we want its kinetic energy to be equal to that of the continent, so

K = 2016 J

Re-arranging the equation for v, we find what speed the jogger needs to have this kinetic energy:

$v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(2016)}{80}}=7.1 m/s$

Learn more about kinetic energy here:

brainly.com/question/6536722

#LearnwithBrainly

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2 years ago

Which phrases describe NASA's goals in the coming years? Check all that apply.

Serggg [28]

Answer:

1, 3 and 4

Explanation:

Did the test and saw the answers.

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KonstantinChe [14]

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1 year ago

Paul and Ivan are riding a tandem bike together. They’re moving at a speed of 5 meters/second. Paul and Ivan each have a mass of

Tresset [83]

Answer: Well they could go down a hill to gain more kinetic energy, or the answer can just be B. He can pedal harder to increase the rate to 10 meters/second. I hope I helped you.

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1 year ago

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