Answer:
Night vision is the ability to see in low-light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range.
Answer:
Explanation:
velocity of sound in air at 20⁰C is 343 m /s
velocity of sound in water at 20⁰C is 1481 m /s
The wavelength of the sound is 2.86 m in the air so its frequency
= 343 / 2.86 = 119.93 .
This frequency of 119.93 will remain unchanged in water .
wavelength in water = velocity in water / frequency
= 1481 / 119.93
= 12. 35 m .
Answer:
22.17 degree
Explanation:
n = 1.52
Angle of incidence, i = 35 degree
Let the angle of refraction is r.
use the Snell's law
n = Sin i / Sin r
Sin r = Sin i / n = Sin 35 / 1 .52
Sin r = 0.37735
r = 22.17 degree
Thus, the ray is refracted at an angle of 22.17 degree.
Answer:
vf = 14.2176 m/s
Explanation:
Given
m = 4 Kg
viy = 7.00 ĵ m/s
Fx = 11.0 î N
t = 4.5 s
vf = ?
Using the Impulse - Momentum Theorem, we have
F*Δt = m*Δv ⇒ F*Δt = m*(vf - vi)
⇒ vf = (F*Δt + m*vi) / m
⇒ vf = (F*Δt + m*vi) / m
For <em>x-component</em>
⇒ vfx = (Fx*Δt + m*vix) / m = (11 N*4.5 s + 4 Kg*0 m/s) / (4 Kg)
⇒ vfx = 12.375 î m/s
For <em>y-component</em>
⇒ vfy = (Fy*Δt + m*viy) / m = (0 N*4.5 s + 4 Kg*7 m/s) / (4 Kg)
⇒ vfy = 7 ĵ m/s
Finally:
vf = √(vfx² + vfy²)
⇒ vf = √((12.375 m/s)² + (7 m/s)²)
⇒ vf = 14.2176 m/s