Answer:
The angle of refraction is 41.68°.
Explanation:
The refractive index for water is 
, and for air 
: the angle of light with the normal is 
; therefore Snell's law gives
Answer:
The average speed would be the 200 miles/4 hours.
The average velocity would be the net displacement to the north at 80 miles/4 hrs = mph
Explanation:
Answer:
The answer would be A. The waves that heat a cup of water in a microwave oven
Answer:
The length of her shadow is changing at the rate -2 m/s
Explanation:
Let the height oh the street light, h = 22 ft
Let the height of the woman, w = 5.5 ft
Horizontal distance to the street light = l
length of shadow = x
h/w = (l + x)/x
22/5.5 = (l + x)/x
4x = l + x
3x = l
x = 1/3 l
taking the derivative with respect to t of both sides
dx/dt = 1/3 dl/dt
dl/dt = -6 ft/sec ( since the woman is walking towards the street light, the value of l is decreasing with time)
dx/dt = 1/3 * (-6)
dx/dt = -2 m/s
Answer:
D. A dry cell battery
Explanation:
A dry cell is a type of electric battery, commonly used for portable electrical devices. It was developed in 1886 by the German scientist Carl Gassner, after development of wet zinc-carbon batteries by Georges Leclanché in 1866.
