Understanding Physics questions (1 Viewer)

[Zuroy]

Hi,

For those who do/completed physics, how do you grasp the worded questions?
The questions are worded in such a way that it confuses me and I have no idea which formula to use.

For example:
A fully dressed astronaut, weighting 1.2 x 10(3)(cubed) N on earth, is about to jump down from a space capsule which has just landed safely on Planet X. The drop to the surface of X is 2.8 m, and the astronaut’s potential energy relative to the surface is 1.1 x 10(3)(cubed) J.

(a) What is the acceleration due to gravity on planet X?
(b) How long does the jump take?
(c) What is the astronaut's maximum velocity?

How am I suppose to figure it out which formula and information to use when i barely even get the question. I understand what the question is saying but its phrased in such a weird/confusing way that i dont have a clue on what to do

Please help. Thanks

 

[iRuler]

Try drawing it, or turning it into complete numbers.

 

[Hope_]

A) Earth's gravitational pull is 9.8m/s^2, so the mass of the astronaut is 1200N / 9.8 = 122.45kg. The weight of the astronaut is 1100N on Planet X, and so the gravitational potential pull is 1100 / 122.45 = 8.98m/s^2

B) Using s= ut + .5at^2 ... 2.8m = 0 + .5*8.98*t^2
--- From this we can calculate t= 0.79s

C) We know that maximum velocity is just before he lands because the potential kinetic energy is lowest. The velocity can be calculated by v= u + at | v= 0+ 2.8*0.79
--- From this we can calculate that v = 2.2m/s

Hope it helps.

 

[Zuroy]

I get it now that you've explained it.
But how do you figure out which formula to use?
Does it just come with practice?

 

[Kaiser_2o1o]

Just identify what you need to find, and what variables/constants you have.