Question

1. mateo and jackie were on a playground rolling some different - sized balls to get them to crash. they used a tennis ball (the same mass) in both crashes. they tried two soccer balls - a pink one (more mass) for crash 1 and a blue one (less mass) for crash 2.

mateo and jackie want to know what happened to the tennis ball. use information from the diagram to answer.
in which crash did the tennis ball experience a stronger force? how do you know?
a crash 1: the force on the soccer ball was stronger in this crash, so the force on the tennis ball was also stronger.
b there was no force on the tennis ball. in each crash only on the soccer ball experienced a force.
c it was the same in both crashes. the soccer ball changed speed by the same amount in each crash, so the force on the tennis ball was the same both times.
d the diagram doesnt tell you anything about the force on the tennis ball. it only gives information about the force on the soccer balls.

Explanation:

Step1: Analyze the concept of force in collisions

According to Newton's third law of motion, when two objects collide, the forces they exert on each other are equal in magnitude and opposite in direction. But in this case, we are looking at the effect of mass on the force experienced by the tennis ball. The force on an object is related to its change in momentum ($F = \frac{\Delta p}{\Delta t}=\frac{m\Delta v}{\Delta t}$). When the soccer ball (with different masses in two crashes) collides with the tennis ball, a more massive soccer ball (pink one in Crash 1) will cause a greater change in the tennis ball's motion (assuming similar collision times). Since the soccer ball in Crash 1 (pink - more mass) caused a situation where if we consider the interaction, the force on the tennis ball is related to how much the soccer ball (which is interacting with it) is affected. A more massive soccer ball, when it collides, will exert a stronger force on the tennis ball (because of the nature of the interaction and the relationship between mass and change in motion as per $F = ma$ - Newton's second law, and the fact that forces in interaction pairs are related). In Crash 1, the soccer ball is more massive. If we assume the collision time is similar for both crashes, a more massive soccer ball (in Crash 1) will have a greater tendency to change the tennis ball's motion (because from $F=\frac{m\Delta v}{\Delta t}$, for the soccer - tennis ball system, a more massive soccer ball will lead to a greater force on the tennis ball as per the interaction).

Step2: Evaluate each option

• Option a: Crash 1: the force on the soccer ball was stronger in this crash, so the force on the tennis ball was also stronger. This is correct because of the interaction (Newton's third law - the force on the soccer ball and tennis ball are an action - reaction pair. If the force on the more massive soccer ball is stronger (based on its mass - force relationship $F = ma$, assuming acceleration is related to the change in its own motion during the collision), then the force on the tennis ball (its reaction force) is also stronger).
• Option b: There was no force on the tennis ball. In each crash only on the soccer ball experienced a force. This is wrong because in a collision (an interaction), both objects experience forces (Newton's third law).
• Option c: It was the same in both crashes. The soccer ball changed speed by the same amount in each crash, so the force on the tennis ball was the same both times. This is wrong because the soccer balls have different masses (pink - more mass in Crash 1). Using $F = ma$, if the acceleration (change in speed over time) of the soccer ball is considered (even if we assume some relation to the force), a more massive soccer ball (in Crash 1) would imply a different force (since $a=\frac{F}{m}$, for a given $a$ (which is not necessarily the same as the problem doesn't state same acceleration), but considering the interaction, the force can't be the same as masses are different).
• Option d: The diagram doesn't tell you anything about the force on the tennis ball. It only gives information about the force on the soccer balls. This is wrong because of Newton's third law - forces in an interaction are related. If we can say something about the force on one object (soccer ball, related to its mass - force relationship), we can say something about the force on the other (tennis ball) as they are an action - reaction pair.

Answer:

A. Crash 1: the force on the soccer ball was stronger in this crash, so the force on the tennis ball was also stronger.