A. How did doubling the force affect the acceleration of the cart?

Answer 1

According to Newton's second law of motion, acceleration (a) is directly proportional to the net force (F) acting on an object and inversely proportional to its mass (m). This relationship is expressed by the formula:

$$F=m\cdot a$$

If you double the force acting on the cart while keeping its mass constant, the acceleration of the cart will also double.

For example, if the original force applied to the cart results in an acceleration of $a$, then applying a force of $2F$ will result in an acceleration of $2a$:

$$2F=m\cdot (2a)$$

In conclusion, doubling the force applied to the cart will double its acceleration, assuming the mass of the cart remains unchanged.