warm fluids are less dense than cold fluids
The work done is 375 J
Explanation:
The work done by a force in moving an object is given by

where
F is the magnitude of the force
d is the displacement
is the angle between the direction of the force and the displacement
In this problem,
F = 75 N is the force applied to the couch
d = 5 m is the displacement
Assuming the force applied to the couch is parallel to the motion, 
And so, the work done is

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What is being done in shaping is that it directs and guides the change in one's behavior. Therefore, what will happen when one undergoes shaping is that you encourage a lot of minor behaviors which would add up to one large action. The answer to this would be the first option.
In a moving car the outside looks to be moving. however if viewed from the outside, the car appears to be moving. so motion is relative to the person observing.
Answer:
457.81 Hz
Explanation:
From the question, it is stated that it is a question under Doppler effect.
As a result, we use this form
fo = (c + vo) / (c - vs) × fs
fo = observed frequency by observer =?
c = speed of sound = 332 m/s
vo = velocity of observer relative to source = 45 m/s
vs = velocity of source relative to observer = - 46 m/s ( it is taking a negative sign because the velocity of the source is in opposite direction to the observer).
fs = frequency of sound wave by source = 459 Hz
By substituting the the values to the equation, we have
fo = (332 + 45) / (332 - (-46)) × 459
fo = (377/ 332 + 46) × 459
fo = (377/ 378) × 459
fo = 0.9974 × 459
fo = 457.81 Hz