What Is the Maximum Angle Attained by a Particle Projected from Earth?

[harambe]

Homework Statement

A particle is projeccted from the surface of the Earth with an initial speed of 4km/s.Find the maximum angle attained by the particle.Radius of the earth=6400km and g=9.8m/s2

Homework Equations

KE1+U1=KE2+U2
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The Attempt at a Solution

So I tried to proceed by this method

1/2{mv2} - GMm/R=-GM/(R+H)

Is my equation right?

[/B]

 

[Dr Dr news]

You have the kinetic energy and the force/mass (which is the local acceleration due to gravity) in the same equation. So yes, your equation is incorrect. You are looking for the conservation of the total energy.

 

[harambe]

Oops .I had to use potential energyIs it right now

 

[Dr Dr news]

If you are trying to calculate the altitude above the surface of the Earth, then almost. Take another look at the RHS of your equation..

 

[haruspex]

Find the maximum angle

Angle? Altitude maybe?
As Dr Dr news mentions, you have a typo in your equation.

 

[harambe]

1/2{mv2} - GMm/R=-GMm/(R+H)
Is this correct

 

[Dr Dr news]

That looks good.