When light is reflected by a mirror, the angle of incidence is always <span>A. equal to the angle of reflection. We know this by the Law of Reflection.</span>
Answer:
the required revolution per hour is 28.6849
Explanation:
Given the data in the question;
we know that the expression for the linear acceleration in terms of angular velocity is;
= rω²
ω² =
/ r
ω = √(
/ r )
where r is the radius of the cylinder
ω is the angular velocity
given that; the centripetal acceleration equal to the acceleration of gravity a
= g = 9.8 m/s²
so, given that, diameter = 4.86 miles = 4.86 × 1609 = 7819.74 m
Radius r = Diameter / 2 = 7819.74 m / 2 = 3909.87 m
so we substitute
ω = √( 9.8 m/s² / 3909.87 m )
ω = √0.002506477 s²
ω = 0.0500647 ≈ 0.05 rad/s
we know that; 1 rad/s = 9.5493 revolution per minute
ω = 0.05 × 9.5493 RPM
ω = 0.478082 RPM
1 rpm = 60 rph
so
ω = 0.478082 × 60
ω = 28.6849 revolutions per hour
Therefore, the required revolution per hour is 28.6849
Answer:
1 ) Warm air
2) Cold air
3) Cold water
4) Steel
5) Hot molten
Explanation:
In order to solve this problem, we have to warn that the sound propagates more easily in denser media, in this way we have to identify the densities of the different materials.
Density cold air = 1.2 [kg/m^3]
Density warm air = 1.01 [kg/m^3]
Density cold water = 1000 [kg/m^3]
Density steel = 7500 [kg/m^3]
Density hot molten = 14100 [kg/m^3]
Therefore in order from the slowest to the fastest:
1 ) Warm air
2) Cold air
3) Cold water
4) Steel
5) Hot molten