all models have limitations because they do not duplicate a real system exactly. Which of the following is a limitation of the heliocentric model above in describing the system​

Which two objects have the greatest gravitational force acting between them

Atrain departs from its station at a constant acceleration of 5 m/s. what is the speed of the train at the end of 20s?

What is the electric force acting between two charges of -0.0045 c and -0.0025 c that are 0.0060 m apart? use fe=kq1q2/r^2 and k = 9.00 x 10^9 n*m^2/c^2 a. 1.7 x 10^7 n b. -1.7 x 10^7 n c. -2.8 x 10^9 n d. 2.8 x 10^9 n