Answer:
airplane speed 135mph windspeed 45 mph
Explanation:
This information helps us to write down a system of linear equations
When going head wind, the speed of the wind is substracted from that of the airplane and on the return trip it is added, then:
A:=Airlplane speed
W:= Wind speed
(A+W)*1h=180mi (1)
(A-W)*2h=180mi (2)
then from (1) A=180-W (3), replacing this in (2) we get (180-W-W)*2h =180mi, then
360-4W=180, or 180=4W, then W=45 mph. Replacing this in (3) we have that A=180-45=135 mph.
Answer:
option A
Explanation:
Given,
wavelength of light,
refractive index of gasoline, n₁ = 1.40
Refractive index of water, n₂ = 1.33
thickness of the film, t = ?
Condition of constructive interference is given by
For minimum thickness of the film m = 0
From the question we can clearly observe that phase change from gasoline to air
so, n = 1.4
Hence, the correct answer is option A
Answer:
1/√2
Explanation:
Kinetic energy of a body is expressed as
KE = 1/2mv²
If it's KE is doubled
2KE = 1/2mv1² where v1 is the new speed when the kinetic energy is doubled
To know the value of the amount the velocity has changed, we will divide both equations
2KE/KE = (1/2mv²)/(1/2mv1²)
2 = v²/v1²
(v/v1)² = 2
v/v1 = √2
v1 = v/√2
v1 = 1/√2 × v
The new velocity has changed by
1/√2vinitial
