Answer:
The velocity of sound of an echo is given as:
v = 2d/t, where d is the distance the sound source and the reflecting surface.
The time take for the stroke to be heard is 2s, because the rate is one stoke per second(one stroke in 1s). It means it will be heard after 2s, after the reflection of the sound wave.
v is speed of sound in air(Value 240m/s)
Therefore, d = vt/2 = (340 x 2)/2
d = 340m.
Sally is 340m away.
Explanation:
The above question is an application of echo.
Echo is a sound heard after the reflection of sound wave.
The distance covered will be twice the distance between the source of the sound and the reflecting surface. This is because the sound will travel a certain distance to a reflecting surface and travels back equal distance to the source after getting reflected.
Answer:
2.538 liters of mercury inside each flask
Explanation:
Let the mercury density be 13593 kg per cubic meters. The volume of the mercury contained in flasks that weight 34.5 kg each would be its mass divided by the density
V = 34.5 / 13593 = 0.002538 cubic meter or 2.538 liters
Answer:
The index refraction of the unknown material is 1.08
Explanation:
Light has characteristics of a wave. When light travels or propagates through two media with different index of refraction, the light will bend or will change its speed.
Using Snells' law which is stated mathematically as:
n1Sintheta1 = n2Sinthetha2
Given:
n1 = 1.17
Theta1 = 40.1° = angle of incidence
Theta2 = 36.3° = angle of refraction
n2 = unknown
Substituting into the equation
n1Sin40.1 = 1.17Sin36.3°
0.6441n1 = 0.6937
n1 = 0.6937/0.6441
n1 = 1.08
A moment causes a rotation about or axis. If the moment is to be taken about a point due to a force F, then in order for a moment to develop, the line of action cannot pass through that point...... the total moment was zero because the moment arm was zero as well