A 3Kg projectile is fired straight upward from earth's surface with a speed that is one-fourth the escape speed. Neglecting air resistance.
a) What is the Kinetic energy of this projectile when it is launched?
b) what is the gravitational potential energy of this projectile when it is launched?
c) what is the total mechanical energy of this projectile?
D) what is the highest altitude reached by this projectile, measured from the earth's surface.
Now I know how to solve part A, and part c is part A + part B, I know part B
I know part B formula but I don't know which mass to plug in for m2? I have no idea how to solve part D? please help.
Escape velocity is 36,685fps.
36,685/4 = 9171.25fps.
From Vf = Vo - gt, 0 = 9171.25 - 32.2t making the time to Vf = 0 284.82sec.
The height reached then derives from
h = Vo(t) - gt^2/2 =
...9171.25(284.820 - 32.2[(284.82)^2]/2
To find the gravitational potential energy of the projectile when it is launched, you need to consider the height above the Earth's surface.
The formula for gravitational potential energy is given by:
PE = mgh
where:
PE is the gravitational potential energy,
m is the mass of the projectile,
g is the acceleration due to gravity, and
h is the height above the Earth's surface.
In this case, the projectile is launched from the Earth's surface, so h is zero.
Therefore, the gravitational potential energy at launch (part B) is zero, since the height is zero.