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Neporo4naja [7]
2 years ago
11

PLEASE HELP ME WITH THIS PROBLEM

Physics
1 answer:
valentinak56 [21]2 years ago
3 0

1) The mass of the continent is 2.13\cdot 10^{21} kg

2) The kinetic energy of the continent is 274.8 J

3) The speed of the jogger must be 2.76 m/s

Explanation:

1)

The continent is a slab of side 5900 km (so the surface is 5900 x 5900, assuming it is a square) and depth 26 km, therefore its volume is:

V=(36)(4600)^2=7.62\cdot 10^8 km^3 = 7.62\cdot 10^{17} m^3

The mass of the continent is given by

m=\rho V

where:

\rho = 2790 kg/m^3 is its density

V=7.62\cdot 10^{17} m^3 is its volume

Substituting, we find the mass:

m=(2790)(7.62\cdot 10^{17})=2.13\cdot 10^{21} kg

2)

To find the kinetic energy, we need to convert the speed of the continent into m/s first.

The speed is

v = 1.6 cm/year

And we have:

1.6 cm = 0.016 m

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

So, the speed is

v=\frac{0.016 m}{3.15 \cdot 10^7 s}=5.08\cdot 10^{-10}m/s

Now we can find the kinetic energy of the continent, which is given by

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

where

m=2.13\cdot 10^{21} kg is the mass

v=5.08\cdot 10^{-10}m/s is the speed

Substituting,

K=\frac{1}{2}(2.13\cdot 10^{21})(5.08\cdot 10^{-10})^2=274.8 J

3)

The jogger in this part has the same kinetic energy of the continent, so

K = 274.8 J

And its mass is

m = 72 kg

We can write his kinetic energy as

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

where

v is the speed of the man

And solving the equation for v, we find his speed:

v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(274.8)}{72}}=2.76 m/s

Learn more about kinetic energy:

brainly.com/question/6536722

#LearnwithBrainly

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