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2 years ago

A car moved 40 km north and 90 km south. What is the displacement of the car?

Physics

1 answer:

il63 [147K]2 years ago

8 0

Answer:

A. 50 km south

Explanation:

hope this helps!

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A student walks 4 blocks east, 7 blocks west, 1 block east and then 2 blocks west in an hour what is their velocity

Nutka1998 [239]

Answer:

4 blocks west is final displacement. So 4 blocks per hour

3 0

2 years ago

Sound from a source vibrating at frequency 200 Hz travels at the speed of 300 m/s in air.Wavelength of the sound is (in m/s)

natima [27]

It’s
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2 years ago

A 525 kg satellite is in a circular orbit at an altitude of 575 km above the Earth's surface. Because of air friction, the satel

Dafna1 [17]

Answer:

$1.69\cdot 10^{10}J$

Explanation:

The total energy of the satellite when it is still in orbit is given by the formula

$E=-G\frac{mM}{2r}$

where

G is the gravitational constant

m = 525 kg is the mass of the satellite

$M=5.98\cdot 10^{24}kg$ is the Earth's mass

r is the distance of the satellite from the Earth's center, so it is the sum of the Earth's radius and the altitude of the satellite:

$r=R+h=6370 km +575 km=6945 km=6.95\cdot 10^6 m$

So the initial total energy is

$E_i=-(6.67\cdot 10^{-11})\frac{(525 kg)(5.98\cdot 10^{24} kg)}{2(6.95\cdot 10^6 m)}=-1.51\cdot 10^{10}J$

When the satellite hits the ground, it is now on Earth's surface, so

$r=R=6370 km=6.37\cdot 10^6 m$

so its gravitational potential energy is

$U = -G\frac{mM}{r}=-(6.67\cdot 10^{-11})\frac{(525 kg)(5.98\cdot 10^{24}kg)}{6.37\cdot 10^6 m}=-3.29\cdot 10^{10} J$

And since it hits the ground with speed

$v=1.90 km/s = 1900 m/s$

it also has kinetic energy:

$K=\frac{1}{2}mv^2=\frac{1}{2}(525 kg)(1900 m/s)^2=9.48\cdot 10^8 J$

So the total energy when the satellite hits the ground is

$E_f = U+K=-3.29\cdot 10^{10}J+9.48\cdot 10^8 J=-3.20\cdot 10^{10} J$

So the energy transformed into internal energy due to air friction is the difference between the total initial energy and the total final energy of the satellite:

$\Delta E=E_i-E_f=-1.51\cdot 10^{10} J-(-3.20\cdot 10^{10} J)=1.69\cdot 10^{10}J$

8 0

2 years ago

A joule is a unit of work is equal to ____?

Artemon [7]

Work is defined as a Newton * meter.

8 0

2 years ago

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Help this was due yesterday...

insens350 [35]

Answer:

Concept: Periodic Trends

So we have Li and we have C
Li has is lower in the periodic table and as you progress from s group to p group and eventually d group, the traction and ability to attract electrons increases.
Hence option D

3 0

2 years ago

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