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:
18min
Explanation:
v=d/t
t=d/v= 27/90 =0.3hrs =18min
Velocity is a speed AND a direction.
When you turn a corner, or go around a curve in the road, your
direction changes, but the reading on the dial doesn't change.
So it can't be showing velocity. It must be showing only speed.
That's probably a big part of the reason why it's called a speedometer
and not a velocimeter.
Answer:
The force is 274 N.
Explanation:
In figure 2:
(d) Let the tension in the string is T.
According to the Newton's second law,
Net force = mass x acceleration
Apply for 200N.
Now put in (1)
T - 114.7 = 20.4 x 7.81
T = 274 N
