In: Physics
A projectile is launched vertically from the surface of the Moon with an initial speed of 1290 m/s. At what altitude is the projectile's speed one-fifth its initial value?
Hey there!
First let me give you the formula for the Vertical distance and the vertical velocity of a projectile.
Where,
the velocity along the y-axis is Vy ,
the initial velocity along the y-axis is Vy1 .
acceleration due to gravity is g, and
the time taken is t.
The acceleration due to gravity in moon is g= 1.6 m/s2 and given that the initial velocity Vy1 = 1290 m/s.
First let us find the time taken to reach one fifth of the velocity Vy1 ,that is Vy1 / 5 = 1290 / 5 = 258 m/s
Hence Vy = 258 m/s
hence the time taken to reach that velocity should be ,
Hence
Applying t = 645 in the first formula we get the vertical distance as
Hence the height at which the velocity would become one fifth of the initial velocity would be 499.23 km.
I hope the solution helps.... Feel free to comment and discuss further... Cheers :)