Mass and velocity of course
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Below are the choices that can be found from other source:
<span>A. The total momentum of the system is conserved.
</span><span>B. The total momentum of the system is not conserved.
</span><span>C. The total momentum of the system is zero.
</span><span>D. The total momentum of the system is negative.
</span>
The answer is A.
The work done on the block is B) 400 J
Explanation:
The work done when lifting an object is equal to the change in gravitational potential energy of the object:
where
m is the mass of the object
g is the acceleration of gravity
is the change in height of the object
In this problem we have:
(mg) = 100 N is the weight of the block (product of mass and acceleration of gravity)
is the change in heigth of the object
Substituting, we find the work done:
Learn more about work:
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The change in frequency is called the Doppler effect. The speed of the car can be calculated by the formula for the Doppler effect for when the observer is standing still and the source of the sound is moving towards him:
f¹={V/(V-Vs)}*f,
where f¹ is the frequency of the car while moving towards the observer, V=343 m/s is the speed of sound, Vs is the speed of the car and f is the frequency of the car while standing still.
We need to solve the equation for the Vs:
f¹/f=V/(V-Vs)
V-Vs=V/(f/f¹)
-Vs=V/(f/f¹)-V
Vs=-V/(f/f¹)+V= -343/(300/330)+343=-343*0.91+343=-312.1+343=30.9 m/s
So the speed of the moving police car is Vs=30.9 m/s.
Pull into the lot of a place that's 24 hours therefor if a office drives by its just a car