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3 years ago

14

A 380-N girl walks down a flight of stairs son that she is 2.5 m below her starting level. What is the change in the girl's grav

itational potential energy?

1 answer:

Olenka [21]3 years ago

5 0

Gravitational potential energy equals mass*gravity*height At the starting level her gpe is 0 At2.5m below plg in 2.5 for height

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When a board with a box on it is slowly tilted to larger and larger angle, common experience shows that the box will at some poi

nydimaria [60]

Answer:

Correct option is A - The force of kinetic friction is smaller than that of static friction, but Fg remains the same.

Explanation:

(A) The force of kinetic friction is smaller than that of static friction, but Fg remains the same

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4 years ago

One electron collides elastically with a second electron initially at rest. After the collision, the radii of their trajectories

morpeh [17]

Answer:

63.750KeV

Explanation:

We are given that

Initial velocity of second electron, $u_2=0$

Radius, $r_1=0$

$r_2=2.3 cm=\frac{2.3}{100}=0.023 m$

1 m=100 cm

Magnetic field,B=0.0370 T

We have to determine the energy of the incident electron.

Mass of electron, $m=9.1\times 10^{-31} kg$

Charge on an electron, $q=-1.6\times 10^{-19} C$

Velocity, $v=\frac{Bqr}{m}$

Using the formula

Speed of electron, $v_1=\frac{Bqr_1}{m}=\frac{0.0370\times 1.6\times 10^{-19}\times 0}{9.1\times 10^{-31}}=0$

Speed of second electron, $v_2=\frac{0.0370\times 1.6\times 10^{-19}\times 0.023}{9.1\times 10^{-31}}$

$v_2=1.5\times 10^8 m/s$

Kinetic energy of incident electron= $\frac{1}{2}mv^2_1+\frac{1}{2}mv^2_2$

Kinetic energy of incident electron= $0+\frac{1}{2}(9.1\times 10^{-31})(1.5\times 10^8)^2=1.02\times 10^{-14} J$

Kinetic energy of incident electron= $\frac{1.02\times 10^{-14}}{1.6\times 10^{-19}}=63750eV=\frac{63750}{1000}=63.750KeV$

1KeV=1000eV

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3 years ago

Explain the benefits of understanding sound waves properties in real life.

Tems11 [23]

Answer:

The vibrations from sound waves cause our ears to send signals to our brains to create sound. The speed of sound waves will determine the sound's pitch, or how high or low something sounds. Sound waves are important because they allow us to hear important messages and emergency signals to protect ourselves.

Explanation:

I hope this helps :)

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3 years ago

At what time of year is the intensity of solar radiation striking each of earth's hemispheres weakest?

bagirrra123 [75]

<span>During winter for a given hemisphere, solar radiation reaches the lowest period of its annual cycle due to the tilt of the earth on its axis. As the earth rotates around the sun, this tilt occludes a portion of the energy released by the sun as it diffuses in the atmosphere.</span>

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3 years ago

What is the critical angle of light traveling from benzene (n=1.501) into air?

Taya2010 [7]

The critical angle formula should be: sin^-1(1/n)

where "n" is 1.501 into the air

<span>The critical angle of light travelling from benzene, happens because the larger angles of incidence from the inside of the benzene has experienced the total internal reflection. </span>

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4 years ago