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3 years ago

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Adolf and Ed are wearing harnesses and are hanging at rest from the ceiling by means of ropes attached to them. Face to face, th

ey push off against one another. Adolf has a mass of 120 kg, and Ed has a mass of 70 kg. Following the push, Adolf swings upward to a height of 0.52 m above his starting point. To what height above his own starting point does Ed rise?

1 answer:

Alex3 years ago

6 0

Explanation:

It is given that,

Mass of Adolf, $m_1=120\ kg$

Mass of Ed, $m_2=70\ kg$

Adolf swings upward to a height of 0.52 m above his starting point. Initially both men are at rest. Their momentum will remain conserved.

Firstly, finding the speed of Adolf by using the conservation of energy as :

$mgh=\dfrac{1}{2}mv^2$

$v=\sqrt{2gh}$

$v=\sqrt{2\times 9.8\times 0.52}$

v = 3.19 m/s

Let v' is the speed of Ed. It can be calculated using the conservation of momentum as :

$m_1v+m_2v'=0$

$v'=-\dfrac{m_1v}{m_2}$

$v'=-\dfrac{120\times 3.19}{70}$

v' = -5.46 m/s

Let H is the height above which Ed rise. It can be calculated using the conservation of energy again as:

$H=\dfrac{v^2}{2g}$

$H=\dfrac{(-5.46)^2}{2\times 9.8}$

H = 1.52 meters

So, Ed will rise to a height of 1.52 meters. Hence, this is the required solution.

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Answer:

$h=\dfrac{3v^2}{8g}$

Explanation:

It is given that,

Speed of the projectile is 0.5 v. Let h is the height above the ground. Using the first equation of motion to find it.

$v=u+at$

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Initial speed of the projectile is v and final speed is 0.5 v.

$0.5v=v-gt$

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g is the acceleration due to gravity

Let h is the height above the ground. Using the second equation of motion as :

$h=vt-\dfrac{1}{2}gt^2$

$h=v\dfrac{v}{2g}-\dfrac{1}{2}g(\dfrac{v}{2g})^2$

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What is the net force on a 50-newton weight hanging on a string tied to the ceiling?

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For example, when you pedal your bicycle so that its speed increases, you are doing work to transfer chemical energy from your muscles to the kinetic energy of the bicycle.

Kinetic energy is the energy an object possesses by virtue of its movement. The amount of kinetic energy possessed by a moving object depends on the mass of the object and its speed. The greater the mass and the speed of the object the greater its kinetic energy.

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Explanation:

When work is done on an object it may also lead to energy being transferred to the object in the form of gravitational potential energy of the object.

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Two suitcases. One has a green force arrow pointing up labelled F and a purple force arrow pointing down labelled 'Weight = mg'. The other case is raised by a height labelled h.

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E = m \times g \times h

This is the relationship used to calculate gravitational potential energy.

{E_p} = mgh

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