Question

why does the shopping cart become harder to push at the end when there is more stuff in it? explain using newtons second law.

Explanation:

Step1: State Newton's second law

Newton's second law is $F = ma$, where $F$ is force, $m$ is mass, and $a$ is acceleration.

Step2: Analyze the situation

As more stuff is added to the shopping - cart, its mass $m$ increases. To move the cart with a certain acceleration $a$, according to $F=ma$, when $m$ increases and $a$ is kept constant (assuming we want to move the cart at a steady speed or with a certain desired acceleration), the force $F$ we need to apply must increase. So it becomes harder to push.

Answer:

As the mass of the shopping - cart increases with more stuff in it, according to Newton's second law $F = ma$, a greater force is required to achieve the same acceleration, making it harder to push.