Question

A small kid sits on a bike (Anita). A bigger and stronger person (Jamy) pushing the kid so that the kid starts speeding up. (neglect friction). Mark all correct statements about the forces between them.
A. There is automatically a force pushing back from Anita to Jamy.
B. The forces depends on their masses.
C. The force on Anita is zero.
D. The force from Anita to Jamy is equal to the force Jamy pushes on Anita.
E. The force from Anita to Jamy is greater than the force Jamy pushes on Anita.
F. The force on Jamy is zero.
G. The force from Anita to Jamy is smaller than the force Jamy pushes on Anita.

Answer 1

Answer:

A, B, D.

Explanation:

If Jamy pushes on Anita, then by Newton's 3rd Law there will be a reaction force equal in magnitude and opposite in direction. This means that A and D are correct, while C, E, F and G are incorrect. Since the magnitude of any of these forces can be calculated with Newton's 2nd Law, F=ma for either Jamy or Anita, this means that B is correct.