Answer:
A. carbon and boron
Explanation:
Carbon and boron is not an alloy.
An allow forms between metals and metals using their huge electron could.
Carbon is a non-metal, boron is a also a non-metal
Two non-metals combining together does not make an alloy.
Iron, nickel, aluminum are all metals.
A. the medium through which the light travels changes.
Explanation:
Light waves will continue to travel in a straight line in all directions from their source unless the medium through which the light travels changes.
A change in medium causes light to exhibit different properties. Also, when light hits an obstacle, they can be diffracted.
- The way light travels on crossing a boundary differs.
- At the boundary between two medium, light can either be reflected back or refracted when they cross the medium
- This will cause the light rays to bend towards or away from the normal depending on the properties of the medium.
Learn more:
Refraction brainly.com/question/12370040
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12.00 min = 0.2 hr
8.00 min = 0.15 hr
Total distance:
(10.0 km/hr) (0.2 hr) + (15.0 km/hr) (0.15 hr) + (20.0 km/hr) (0.2 hr)
= 8.25 km
Average speed:
(10.0 km/hr + 15.0 km/hr + 20.0 km/hr) / 3
= 15 km/hr
Change in position:
(10.0 km/hr) (0.2 hr) + (15.0 km/hr) (0.15 hr) - (20.0 km/hr) (0.2 hr)
= 0.25 km
Average velocity:
(10.0 km/hr + 15.0 km/hr - 20.0 km/hr) / 3
≈ 1.67 m/s
