Calculating Cumulative Time Changes over 20 Centuries

  • Thread starter Thread starter Fletcher
  • Start date Start date
AI Thread Summary
The discussion centers on calculating the cumulative effect of a uniform increase in the length of the day by 0.0010 seconds per century over 20 centuries. The initial misunderstanding involves incorrectly multiplying the increase per century by the number of centuries, leading to an inaccurate total. The correct approach requires calculating the average increase in length per day and then considering the total number of days across 20 centuries. The book's answer indicates that this cumulative effect results in an increase of 2.1 hours. Understanding the relationship between daily increases and the total number of days is crucial for accurate calculations.
Fletcher
Messages
25
Reaction score
0
The exercise:

Assuming the length of the day uniformly increases by 0.0010s per century, calculate the cumulative effect on the measure of time over 20 centuries.

The answer given in the book:

2.1 hours

My initial thought was 0.001 x 20, but that's apparently wrong. I think I'm missing something basic.
 
Physics news on Phys.org
Everyday it increases uniformly by .001s per century so in one century each day will be .0001s longer. How much total time does this add on in 20 centuries?
 
Fletcher said:
My initial thought was 0.001 x 20, but that's apparently wrong. I think I'm missing something basic.
What you calculated is the increased length of a single day after 20 centuries. What's the average increase per day? How many days in 20 centuries?
 

Thread 'Errors and significant figures'

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...
View full post »
Thread 'A cylinder connected to a hanging mass'

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...
View full post »

Similar threads

Spring Car, Acceleration Problem: Find Spring Constant
Replies
1
Views
2K
Calculating Cumulative Effect of Slowing Earth's Rotation Over 20 Centuries
Replies
3
Views
4K
Physics problem about Earths rotation after 45 centuries
Replies
2
Views
11K
Measurements Calculation Problem
Replies
3
Views
849
Century Growth Problem: Rate of Change
Replies
2
Views
9K
How Does Earth's Slowing Rotation Affect the Length of Our Days Over Centuries?
Replies
1
Views
4K
Find heat loss given metabolic rate in a closed system
Replies
3
Views
2K
Calculate the time at which the object changes direction
Replies
2
Views
3K
Orbit changes, Kepler's Third Law
Replies
6
Views
6K
Average speed over time interval
Replies
9
Views
4K

Hot Threads

Recent Insights

Back
Top