While your anchor-dropping trap may have been effective, it was not enough to co

Question

While your anchor-dropping trap may have been effective, it was not enough to completely thwart the orc raid on the town. Unwilling to leave the town to its fate, you and your party have remained to assist in fending off the rest of the attack. You and one of your more foolhardy party members are on a street that slopes down to a minimum and then back up as shown with your party member on the left. A group of orcs gather at the opposite end of the street. Your party member decides to hop in a nearby abandoned cart and careen down the street towards the oncoming attackers. Recognizing that the orcs are higher up, you tell them this is a stupid idea. In response they pick up a large rock and tell you that they’ll simply drop the rock at the lowest point on the street. Would doing so help them reach the orcs? Why was it initially a stupid idea? Explain without using or referencing any formulas or equations. Assume that dropping the rock would not affect the total mechanical energy of the system.   

Explanation / Answer

Dropping the rock will not help them reach them the orcs. Conservation of energy will imply that the maximum height reached will be the same height as they started. To reach the orcs we will have to increase the total energy, so we can increase the kinetic energy at the bottom of the path. This can be done by increasing the velocity. From conservation of momentum if we drop the rock the rock will continue with same velocity as the cart. So the cart's velocity will not change. So that's why this was a stupid Idea. If we really want to reach the orcs, we have to throw the rock backwards, so from momentum conservation the velocity of cart will increse after rock is thrown.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.