Answer:
the answers the correct one is d
Explanation:
The speed of sound is constant so we can use the relations of uniform motion
v = x / t
x = v t
now let's calculate the distance for each person
t = 5s
x₁ = 300 5
x₁ = 1500 m
t = 6s
x₂ = 300 6
x₂ = 1800 m
therefore we have two possibilities
a) the two people are on the same side, therefore the distance between them is
Δx = x₂- x₁
Δx = 1800 - 1500
Δx = 300 m
let's reduce to km
Δx = 0.300 km
b) people are on opposite sides of the sound
Δx = x₂ + x₁
Δx = 1800 + 1500
Δx = 3300 m
Δx = 3.3 km
when checking the answers the correct one is d
<span>10 hertz
Hertz is the frequency of oscillation which is the number of oscillations per second. So if something takes 0.10 s per oscillation, divide 1 second by the period to get the frequency. So
1 / 0.10s = 10 1/s = 10 Hertz
Therefore the object is vibrating at 10 hertz.</span>
Answer:
The car C has KE = 100, PE = 0
Explanation:
The principle of conservation of energy states that although energy can be transformed from one form to another, the total energy of the given system remains unchanged.
The energy that a body possesses due to its motion or position is known as mechanical energy. There are two kinds of mechanical energy: kinetic energy, KE and potential energy, PE.
Kinetic energy is the energy that a body possesses due to its motion.
Potential energy is the energy a body possesses due to its position.
From the principle of conservation of energy, kinetic energy can be transformed into potential energy and vice versa, but in all cases the energy is conserved or constant.
In the diagram above, the cars at various positions of rest or motion are transforming the various forms of mechanical energy, but the total energy is conserved at every point. At the point A, energy is all potential, at B, it is partly potential partly kinetic energy, However, at the point C, all the potential energy has been converted to kinetic energy. At D, some of the kinetic energy has been converted to potential energy as the car climbs up the hill.
Therefore, the car C has KE = 100, PE = 0
Answer:
1.414
Explanation:
Snell's law states:
n₁ sin θ₁ = n₂ sin θ₂
where n is the index of refraction and θ is the angle of incidence (relative to the normal).
The index of refraction of air is approximately 1. So:
1 sin 45° = n sin 30°
n = sin 45° / sin 30°
n = 1.414
Round as needed.
Answer:
11.8 m/s
Explanation:
At the top of the hill, there are two forces on the car: weight force pulling down (towards the center of the circle), and normal force pushing up (away from the center of the circle).
Sum of forces in the centripetal direction:
∑F = ma
mg − N = m v²/r
At the maximum speed, the normal force is 0.
mg = m v²/r
g = v²/r
v = √(gr)
v = √(9.8 m/s² × 14.2 m)
v = 11.8 m/s
