Question

li and raj are playing football. they take turns trying to run past each other with the football. li weighs 125 pound and raj weighs 175 pounds. li discovers that if he changes direction quickly when running, he can always dodge out of the way before raj can tackle him. why is li able to avoid raj’s tackle? choose the best description. raj has more mass and therefore less inertia, so he can change his motion more easily than li. li has less mass and therefore less inertia, so he can change his motion more easily than raj. raj has more mass and therefore more inertia, so he can change his motion more easily than li. li has less mass and therefore more inertia, so he can change his motion more easily than raj.

Explanation:

To determine why Li can avoid Raj's tackle, we use the concept of inertia: inertia is directly proportional to mass (more mass means more inertia, less mass means less inertia). Inertia is the resistance to changes in motion, so an object with less inertia (less mass) can change its motion (like direction) more easily. Li weighs 125 pounds (less mass) and Raj weighs 175 pounds (more mass). So Li has less mass → less inertia → can change motion (direction) more easily than Raj (who has more mass, more inertia, and thus resists changing motion more).

Let's analyze each option:

• First option: Says Raj (more mass) has less inertia. But inertia is proportional to mass, so more mass means more inertia. So this is wrong.
• Second option: Li (less mass) has less inertia, so can change motion more easily. This matches the inertia - mass relationship.
• Third option: Says Raj (more mass) can change motion more easily. But more inertia (from more mass) means more resistance to changing motion, so he should be harder to change motion. Wrong.
• Fourth option: Says Li (less mass) has more inertia. But less mass means less inertia. Wrong.

Answer:

Li has less mass and therefore less inertia, so he can change his motion more easily than Raj.