Answer:
Explanation:
velocity of the Escalators is given as 6 ft/s
now we know that Jane steps on parallel escalator after t = 5 s
so distance moved by John in same time interval is given as
now John and Jane will move towards each other with relative speed
Then will approach towards each other with this relative speed and meet after t = 15 s
so the distance moved by them
so total length of the escalators is given as
Answer:
(a) 47.08°
(b) 47.50°
Explanation:
Angle of incidence = 78.9°
<u>For blue light :
</u>
Using Snell's law as:
Where,
Θ₁ is the angle of incidence
Θ₂ is the angle of refraction
n₂ is the refractive index for blue light which is 1.340
n₁ is the refractive index of air which is 1
So,
Angle of refraction for blue light = sin⁻¹ 0.7323 = 47.08°.
<u>For red light :
</u>
Using Snell's law as:
Where,
Θ₁ is the angle of incidence
Θ₂ is the angle of refraction
n₂ is the refractive index for red light which is 1.331
n₁ is the refractive index of air which is 1
So,
Angle of refraction for red light = sin⁻¹ 0.7373 = 47.50°.
Answer:
W = 439998 J = 439.99 KJ
Explanation:
First, we will calculate the acceleration of the car by using the first equation of motion:
where,
a = acceleration = ?
vf = final speed = = 30 m/s
vi = initial speed = = 10 m/s
t = time = 30 s
Therefore,
a = 0.67 m/s²
Now, we will calculate the force applied by the engine:
F = ma
where,
F = force = ?
m = mass = 1100 kg
Therefore,
F = (1100 kg)(0.67 m/s²)
F = 733.3 N
Now, we will calculate the distance covered by the car by using the second equation of motion:
s = 600 m
Now, the work done (W) by engine can be calculated as follows:
W = Fs
W = (733.3 N)(600 m)
<u>W = 439998 J = 439.99 KJ</u>