Momentum Comparison: Bob the Bear vs. Wilmer the Watermelon

Which object would be harder to stop?

Bob the Bear is driving a 60,000 [Ibs] (27,200 [kg]) 18-wheeler, going 35 miles per hour (15.6 [m/s]) down a country road.
Wilmer the Watermelon is at the firing range, shooting his sniper rifle, which has a bullet with a mass of .042 [kg] traveling at 2045 miles per hour (928 [m/s]). Which object would be harder to stop?

Final Answer:

The 18-wheeler, driven by Bob the Bear, with its significantly higher momentum, would be much harder to stop than the bullet fired by Wilmer the Watermelon.

Explanation: When considering which object would be harder to stop between Bob the Bear driving an 18-wheeler and Wilmer the Watermelon firing a bullet, we must look at the concept of momentum. Momentum is the product of an object's mass and its velocity. To analyze which one would be more difficult to bring to a stop, we calculate their momenta:

18-wheeler: Momentum = Mass x Velocity = 27,200 kg x 15.6 m/s = 424,320 kg·m/s
Bullet: Momentum = Mass x Velocity = 0.042 kg x 928 m/s = 38.976 kg·m/s

Comparing these two values, the 18-wheeler has significantly more momentum and thus would require much more force to stop, making it much harder to stop compared to the bullet.

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