You drop your backpack out of a window from a height of 8.3 m. what is the impact speed of your backpack?
a. 163 m/s
b. 1.2 m/s
c. 21.3 m/s
d. 12.8 m/s

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

If an atom contains 11 protons in its nucleus, predict the element with the atomic number and electronic configuration. will the number of electrons remain the same during the chemical reaction in such an atom? explain.

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.