A student asks the question: "How does an object's mass affect its motion?" Which of the following is a testable hypothesis for this question

The options are not given, so i will answer in a really general case.

There are two equations that describe how mass affects the motion of an object.

The most generical one, Newton's second equation of motion.

This says that:

F = m*a

Force equals mass times acceleration.

Remember that acceleration tells us how the motion of an object changes as time passes.

So if we isolate the acceleration we get:

a = F/m

Here you can see that the mass is in the denominator, so, for a fixed force F, if we increase the mass of the object, the acceleration will decrease, which means that as more mass has an object, "harder" is to accelerate it.

Now from an energy point of view.

The kinetic energy (the motion energy of a moving object) is written as:

T = (1/2)*m*(v^2)

where:

m = mass

v = velocity.

Here, for a fixed velocity v, if we increase the mass, we also increase the kinetic energy.

This means that if we have two objects, one with a small mass m, and the other with a larger mass M, and we want to give both objects the same velocity v, we will need more energy for the object with more mass.

So in general we can conclude that mass "opposes" to the motion.

Now, we also can define the term "testable"

A hypothesis is testable if we can think of an experiment to test it, if there is no experiment, then the hypothesis is not testable.