Gravitational Interactions » Truck and Car

Click For Summary

Homework Help Overview

The problem involves gravitational interactions between a sports car and a cement truck, specifically calculating the distance between them based on the gravitational force and their masses.

Discussion Character

  • Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss rearranging the gravitational force equation to isolate the distance variable. There are attempts to compute the value of r squared, with some questioning the handling of exponents in the calculations.

Discussion Status

There is ongoing exploration of the calculations involved in determining the distance. Some participants have provided guidance on correcting exponent errors and the next steps to find the distance.

Contextual Notes

Participants are working within the constraints of an online homework assignment, which may influence their approach and the level of detail in their discussions.

Sugi San
Messages
3
Reaction score
0

Homework Statement



i need help with this problem (Online HW)

If the force of attraction between a 1035 kg sports car and a 10680 kg cement truck is 3.930×10-6 N, how far are they apart?

Homework Equations



F = Gm_1m_2/r^2



The Attempt at a Solution

 
Physics news on Phys.org
Where are you stuck? Rearrange that formula to solve for the distance r.
 
r^2 = Gm_1m_2/F

We know m_1 = 1035, m_2 = 10680, F = 3.930 x 10^-6 and G is 6.67300 × 10^-11 m^3 kg^-1 s^-2.

So

r^2 = (6.67300 × 10^-11)(1035)(10680) / (3.930 x 10^-6)

= [(6.67300 )(1035)(10680) / (3.930)] x [10^-11/10^-6]
= [(6.67300 )(1035)(10680) / (3.930)] x 10^-5
= 18768958.6 x 10^-5
= 1876895.86 x 10^-6
= 1.87689586 x 10^-12

so how we find the distance?
 
Sugi San said:
r^2 = (6.67300 × 10^-11)(1035)(10680) / (3.930 x 10^-6)

= [(6.67300 )(1035)(10680) / (3.930)] x [10^-11/10^-6]
= [(6.67300 )(1035)(10680) / (3.930)] x 10^-5
= 18768958.6 x 10^-5
OK.
= 1876895.86 x 10^-6
= 1.87689586 x 10^-12
You are messing up the exponents. When you move the decimal to the left one place you must add +1 to the exponent. You subtracted instead. (Example: 456.7 = 4.567 x 10^2)
so how we find the distance?
Once you correctly find r^2, just take the square root.
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
5K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 25 ·
Replies
25
Views
4K
  • · Replies 9 ·
Replies
9
Views
5K
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 3 ·
Replies
3
Views
5K