How Can an Astronaut Determine Falling Object Acceleration on the Moon?

  • Thread starter Thread starter losolomd
  • Start date Start date
  • Tags Tags
    Love Physics
AI Thread Summary
An astronaut can determine the acceleration of falling objects on the Moon by analyzing the relationship between distance fallen (y) and time elapsed (t) using the equation y = Bt^C. By plotting log(y) against log(t), a linear relationship can be established, allowing for the estimation of constants B and C. The expected values derived from the data suggest B is 1 m/s² and C is 2, indicating that the relationship follows the form y = ½at², where a is the acceleration. This leads to the conclusion that the acceleration of objects dropped on the Moon is approximately 4 m/s². The analysis demonstrates the utility of logarithmic transformations in experimental physics.
losolomd
Messages
3
Reaction score
0

Homework Statement


You are an astronaut doing physics experiments on the moon. You are interested in the experimental relationship between distance fallen, y, and time elapsed, t, of falling objects dropped from rest. You have taken some data for a falling penny, which is represented in the table below.
(a) y (m) 10 20 30 40 50
(b) t (s) 3.5 5.2 6.0 7.3 7.9
You expect that a general relationship between distance y and time t is y = BtC, where B and C are constants to be determined experimentally. To accomplish this, create a log-log plot of the data.
(a) Graph log(y) vs. log(t), with log(y) the ordinate variable and log(t) the abscissa variable. (Do this on paper. Your instructor may ask you to turn in this work.)

(b) Show that if you take the log of each side of your expected relationship, you get log(y) = log(B) + C log(t). (Do this on paper. Your instructor may ask you to turn in this work.)

(c) By comparing this linear relationship to the graph of the data, estimate the values of B and C.
B = 1 m/s2
C = 2

(d) If you drop a penny, how long should it take to fall 1.0 m?
3 s

(e) In the next chapter, we will show that the expected relationship between y and t is y = ½at2, where a is the acceleration of the object. What is the acceleration of objects dropped on the moon?
4 m/s2

Homework Equations


y = BtC


The Attempt at a Solution



log(Y)+ log(t) = log(Y).(t)

 
Physics news on Phys.org


That y=BtC should be y=B*t^C. Taking the logarithm of both sides it is log(y) = log(B) + C log(t). Plot the logarithm of height, log(y) as function of log(t). The point will scatter around a straight line. Either draw the line and read the slope and log(B) from the graph, or determine the constants with linear regression.

ehild
 


Thanks for all your help..
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top