Final answer:
The skateboard that experienced the strongest force when bumped is the one with the greatest change in speed. Force is directly proportional to the acceleration (change in speed), and since all skateboards have the same mass, the one with the greatest speed change felt the strongest force.
Step-by-step explanation:
To determine which skateboard experienced the strongest force when bumped, we must consider the principles of physics related to force, mass, and acceleration. According to Newton's second law of motion (F=ma), the force exerted on an object is equal to the mass of the object multiplied by the acceleration it undergoes. Since Juno, Melissa, and Anna's skateboards have the same mass and different changes in speed, we can infer that the skateboard with the greatest change in speed experienced the greatest force, assuming the time during which the force was applied was the same for all. The correct answer is not provided explicitly in the information given, but using physics principles, we can conclude that the skateboard which changed speed the most experienced the strongest force (option b).
It is important to note that slowing down or speeding up requires force; both are changes in velocity, which indicates a change in speed, direction, or both. Therefore, the statement that it takes a stronger force to slow something down than to speed something up (option a) is not universally true without more context, like the amount of change in speed and direction.
The ending speed alone does not indicate which skateboard experienced the strongest force (option c); without knowing the rate of change from the initial state, this information is not sufficient to conclude which force was strongest.