- #1
rickyjoepr
- 6
- 1
Homework Statement
A saucer of mass 1.75x10^9 enters
1.the gravitational field of PlanetX and enters its atmosphere; the gravitational field of the planet is 10.6 m/s2 and is considered uniform throughout the 80-km thick atmosphere.
If the saucer enters the atmosphere at 460 m/s and slows down to 110 m/s before its crash-landing, what is the average magnitude of the drag force (gravity cannot be neglected)?
[/B]
Homework Equations
drag for disk, D = (1/4) AV^2
W = Total Mechanical Energy
The Attempt at a Solution
E1 = (1/2)m1Vi^2 + mgd
E2 = 0 + 0
So W = (1/2)m1V1+mgd
Because W = Fd
W/d = F
2.55 x10^10
However the correct answer is listed as 2.07 x 10^10 N
I am not sure if my method of using mechanical energy is correct., Or wether I should be using the drag force equation to solve the problem