The correct answer for this problem is c
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. ... Refraction not only affects visible light rays, but all electromagnetic radiation, although in varying degrees.
So in short, the answer is D.
(My answer got deleted because it didnt explain which is dumb)
consider the motion in x-direction
= initial velocity in x-direction = ?
X = horizontal distance traveled = 100 m
= acceleration along x-direction = 0 m/s²
t = time of travel = 4.60 sec
Using the equation
X = t + (0.5) t²
100 = (4.60)
= 21.7 m/s
consider the motion along y-direction
= initial velocity in y-direction = ?
Y = vertical displacement = 0 m
= acceleration along x-direction = - 9.8 m/s²
t = time of travel = 4.60 sec
Using the equation
Y = t + (0.5) t²
0 = (4.60) + (0.5) (- 9.8) (4.60)²
= 22.54 m/s
initial velocity is given as
= sqrt(()² + ()²)
= sqrt((21.7)² + (22.54)²) = 31.3 m/s
direction: θ = tan⁻¹(22.54/21.7) = 46.12 deg
Answer:
μ = 0.33
Equal to 3.2 m/s²
Explanation:
Draw a free body diagram of the block. There are three forces:
Normal force N pushing up.
Weight force mg pulling down.
Friction force Nμ pushing opposite the direction of motion.
Sum of forces in the y direction.
∑F = ma
N − mg = 0
N = mg
Sum of forces in the x direction.
∑F = ma
Nμ = ma
Substitute.
mgμ = ma
μ = a/g
μ = (3.2 m/s²) / (9.8 m/s²)
μ = 0.33
As found earlier, the acceleration is a = gμ. Since g and μ are constant, a is also constant, so it does not change with velocity.
