Two experiments are performed. In (A), an 18.0 N force pushes horizontally on a 2.00 kg block that then pushes on a 4.00 kg block. In (B), an 18.0 N force pushes on a 4.00 kg block that then pushes on a 2.00 kg block. Which statement is correct? A) The acceleration is 3.00 m/s² in both (A) and (B). B) The acceleration is 4.50 m/s² in both (A) and (B). C) The acceleration is 6.00 m/s² in both (A) and (B). D) The acceleration is 9.00 m/s² in both (A) and (B). E) The 2.00 kg block has a 9.00 m/s² acceleration. The 4.00 kg block has a 4.50 m/s² acceleration.

Question

Quizplus · Accepted Answer

The total mass in both experiments is 6.00 kg, and the force applied is 18.0 N. The acceleration can be found using Newton's second law, $F = ma$, which gives $a = \frac{F}{m} = \frac{18.0\,N}{6.00\,kg} = 3.00\,m/s^2$. This calculation is independent of the order of the blocks, so the acceleration is the same in both cases.

Two Experiments Are Performed