Question

A robot probe drops a camera off the rim of a 239 m high cliff on Mars, where the free-fall acceleration is -3.7 m/s^2.
a) Find the velocity with which the camera hits the ground.
b) Find the time required for it to hit the ground.

Ok so I'm not even sure of which equation to use for this problem. Maybe if someone just gave me a hint as to where to begin, I could get the rest...?

Answer 1

vfinal^2 = vinitial62 + 2 a * height
solve for vfinal

vfinal= vinitial + a*t
solve for time.

Memorize these equations.

Answer 2

That should read vinitial^2

my shift finger is getting weak.

Answer 3

Ok so I plugged in the numbers and got 42.1 for a) and -11.4 for b).

However, my book says that I got them switched...that 11.4 s is a) and -42.1 m/s is b). How did this happen?