Use the law of universal gravitation, which says the force of gravitation between two bodies of mass <em>m</em>₁ and <em>m</em>₂ a distance <em>r</em> apart is
<em>F</em> = <em>G m</em>₁ <em>m</em>₂ / <em>r</em>²
where <em>G</em> = 6.67 x 10⁻¹¹ N m²/kg².
The Earth has a radius of about 6371 km = 6.371 x 10⁶ m (large enough for a pineapple on the surface of the earth to have an effective distance from the center of the Earth to be equal to this radius), and a mass of about 5.97 x 10²⁴ kg, so the force of gravitation between the pineapple and the Earth is
<em>F</em> = (6.67 x 10⁻¹¹ N m²/kg²) (1 kg) (5.97 x 10²⁴ kg) / (6.371 x 10⁶ m)²
<em>F</em> ≈ 9.81 N
Notice that this is roughly equal to the weight of the pineapple on Earth, (1 kg)<em>g</em>, where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity, so that [force of gravity] = [weight] on any given planet.
This means that on this new planet with twice the radius of Earth, the pineapple would have a weight of
<em>F</em> = <em>G m</em>₁ <em>m</em>₂ / (2<em>r</em>)² = 1/4 <em>G m</em>₁ <em>m</em>₂ / <em>r</em>²
i.e. 1/4 of the weight on Earth, which would be about 2.45 N.
Answer:
kinetic energy
Explanation:
A wind turbine transforms the mechanical energy of wind into electrical energy. A turbine takes the kinetic energy of a moving fluid, air in this case, and converts it to a rotary motion. As wind moves past the blades of a wind turbine, it moves or rotates the blades. These blades turn a generator
Answer:
168.57 mV
Explanation:
Initial magnetic flux = BA , B magnetic field and A is area of loop
= .35 x 3.14 x .37²
= .15 Weber
Final magnetic flux
= - .2 x 3.14 x .37²
= - .086 Weber
change in flux
.15 + .086
= .236 Weber
rate of change of flux
= .236 / 1.4
= .16857 V
= 168.57 mV
Answer:
turntable with a moment of inertia of 7.2 × − ⋅ rotates freely with an angular speed of 6.5 ⁄ . Riding on the rim of the turntable, 2 from the center, is a hamster. When the hamster walks to the center of the turntable, the angular speed of the turntable becomes ⁄. What is the mass of hamster?
Explanation:
Answer:
D. 2.5 Hz
Explanation:
Frequency = speed of wave / wavelength
= 335 /140 ( from graph)
= 2.4
