Answer: the refraction of light by the atmosphere
Explanation: Refraction is the phenomenon in which there is a change in direction of light passing from one medium to another or from a gradual change in the medium.
Here in case of sunset, the sun rays passes through the varying density of atmosphere because of varying concentrations of dust particles.
Reflection is the phenomenon in which the light bounces back after falling on a surface.
Absorption is the phenomenon in which matter captures the electromagnetic radiations and thus the energy of photons is converted to internal energy of the system.
Explanation:
Displacement = 5 km
A.
Converting km/h to m/s,
10 km/h * 1000 m/1 km * 1 h/3600 s
= 25/9 m/s
Remember,
700 watt = 700 J/s
Velocity = displacement/time
Time = 5000/(25/9)
= 1800 s
Energy = power * time
= 700 * 1800
= 1,260,000
= 1260 kJ
B.
Converting km/h to m/s,
3 km/h * 1000 m/1 km * 1 h/3600 s
= 5/6 m/s
290 watt = 290 J/s
Velocity = displacement/time
Time = 5000/(5/6)
= 6000 s
Energy = power * time
= 290 * 6000
= 1,740,000
= 1740 kJ
C.
Walking burns more energy; 1,740,000 joules. It burns more because you walk for a greater period of time.
Answer:
I = 4.28 [amp]
Explanation:
To solve this type of problems we must have knowledge of the law of ohm, which tells us that the voltage is equal to the product of resistance by current.
Initial data:
v = 1.5 [volt]
R = 0.35 [ohms]
v = I * R
therefore:
I = 1.5 / 0.35
I = 4.28 [amp]
Answer:
distance between the dime and the mirror, u = 0.30 m
Given:
Radius of curvature, r = 0.40 m
magnification, m = - 2 (since,inverted image)
Solution:
Focal length is half the radius of curvature, f =
f =
Now,
m = -
- 2 = -
= 2 (2)
Now, by lens maker formula:
v = (3)
From eqn (2):
v = 2u
put v = 2u in eqn (3):
2u =
2 =
2(u - 0.20) = 0.20
u = 0.30 m