Answer:
v=1.5081 m/s
Explanation:
<u>Uniform Circular Motion
</u>
The cork is performing a circular motion which we assume to be uniform (constant angular speed or angular acceleration zero)
The centripetal force applied to it is given by
where m is the mass and is the centripetal acceleration. This acceleration appears since the tangent speed is constantly changing direction. If w is the angular speed and r is the radius of rotation
The speed of the cork can be found with the formula
We can compute w since we know the rotation period <em>T=1.25 sec
</em>
Now, since r=0.30 m, let's compute v
And finally
4 looks ok
The direction of travel. Q asks for a velocity. Velocity is a vector. Vectors have magnitude and direction.
Answer:
b.) All these technologies use radio waves, including high-frequency microwaves
d.) Microwave ovens emit in the same frequency band as some wireless Internet devices.
e.) The radiation emitted by wireless Internet devices has the shortest wavelength of all the technologies listed above.
f.) All these technologies emit waves with a wavelength in the range of 0.10 to 10.0 m.
Explanation:
For option D. The frequency range of microwave ovens is 2450 MHz = 2.4 GHz, which intersects with wireless internet technology with range of 2.4 to 2.6 GHz.
For E, wavelenght and frequency are inversely proportional. Wireless internet service has the greatest frequency band and hence the shortest wavelenght band.
For F, in all these radiations, the highest Freq is 2.6 GHz and the lowest is 40 MHz. Wavelenght is speed of light (3x10^8 m/s) divided by the frequency.
2.6 GHz = 2.6x10^9 Hz
Wavelenght = 3x10^8 ÷ 2.6x10^9 = 0.1 m
40 MHz = 40x10^6
Wavelenght = 3x10^8 ÷ 40x10^6 = 7.5 m
Answer:
1) Skis have a large area to reduce the pressure on the snow. This ensures that the skis do not sink into the snow too far.
2) The pressure under the studs on the soles of football shoes is high enough for them to sink into the ground, which gives extra grip.
3) A vacuum cleaner has a fan inside that creates a low pressure inside the device. Consequently, air and dirt particles are sucked into the device.
Answer:
C. Nuclear fission of uranium-235