If I am at the station that the train is approaching, and if the train is making some kind of steady sound, then as the train draws closer, I hear the amplitude of the sound steadily increasing ... it gets louder and louder as the train gets closer and closer to me.
(The frequency of the sound I hear is higher than the frequency of the sound the train is actually making, but I don't know that, because I have no idea what frequency sound the train is actually making.)
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If anybody tries to tell you that the frequency of the sound from the train keeps getting higher and higher, please tell that person to come see me, and I will straighten him out. It doesn't.
Erosion is mainly caused by water, wind, and gravity.
Answer:
There would be a pressure drop in the direction of the higher opening. This will force air to move in from the lower opening and force it to leave through the higher opening. This will create a convectional movement of air, cooling and ventilating the tunnel.
Explanation:
This is in accordance with bernoulli's law of fluid flow which states that the pressure exerted by a moving fluid is lesser than it would exert if it were at rest.
Answer: 0.306
Explanation:
from the question we are given the following
mass of sled (m) = 50 kg
force (f) = 1.75 x 10^2 N = 175 N
distance (s) = 6 m
net work done on the sled = 1.50 x 10 ^2 N = 150 N
acceleration due to gravity (g) = 9.8 m/s^2
coefficient of friction = μ
lets first calculate the frictional force (ff)
ff = μ x m x g = μ x 50 x 9.8 = 490 μ
work done on the slide by the applied force (W1)= f x s = 175 x 6 = 1050 j
work done on the slide by frictional force (W2) = ff x s = 490 μ x 6 = 2940μ j
now the net work done is the work done by the frictional force subtracted from the work done by the applied force
net work done = W1 - W2
150 = 1050 - 2940μ
2940μ = 1050 - 150
μ = 900 / 2940
μ = 0.306