/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 101 You are standing on a concrete s... [FREE SOLUTION] | 91Ó°ÊÓ

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You are standing on a concrete slab that in turn is resting on a frozen lake. Assume there is no friction between the slab and the ice. The slab has a weight five times your weight. If you begin walking forward at 2.00 \(\mathrm{m} / \mathrm{s}\) relative to the ice, with what speed, relative to the ice, does the slab move?

Short Answer

Expert verified
The slab moves at 0.40 m/s opposite to your direction.

Step by step solution

01

Consider Conservation of Momentum

The initial momentum of the system (you and the slab) is zero since both you and the slab are at rest. By the principle of conservation of momentum, the total momentum after you start walking must also be zero.
02

Establish Variables and Equations

Let your mass be \( m \) and your velocity relative to the ice be \( v = 2.00 \, \text{m/s} \). The mass of the slab is \( 5m \). Let the velocity of the slab relative to the ice be \( u \). The equation for conservation of momentum is:\[ m \cdot v + 5m \cdot (-u) = 0 \]
03

Solve for the Velocity of the Slab

Re-arrange the equation \( m \cdot v = 5m \cdot u \) to solve for \( u \):\[ u = \frac{v}{5} \]Substitute \( v = 2.00 \, \text{m/s} \) into the equation:\[ u = \frac{2.00}{5} = 0.40 \, \text{m/s} \]
04

Conclusion

The velocity of the slab, relative to the ice, is \( 0.40 \, \text{m/s} \) in the opposite direction to your walking.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Physics Problem Solving
In physics problem-solving, understanding the core concepts and laws is crucial. One effective method is to break down the problem into manageable steps that make it easier to analyze and solve. This involves identifying the given variables, applying relevant physics principles, and logically working through the equations.
For instance, in our exercise, we focus on the conservation of momentum—a central principle in mechanics. We start by recognizing the system components: you and the slab. Knowing that initially both are at rest, thus their combined momentum is zero, sets the stage for application of the physics laws.
Breaking down tasks into steps like defining variables, setting equations, and solving for unknowns is a reliable strategy for tackling such exercises.
Relative Velocity
The concept of relative velocity is key to understanding motion within different frames of reference. It allows us to describe how fast one object moves in relation to another. This is particularly useful when analyzing systems where multiple objects interact, such as a person walking on a slab.
In our scenario, even though you are moving at 2.00 m/s relative to the ice, the slab moves in the opposite direction. The slab's motion relative to the ice compensates for your movement to maintain momentum conservation.
Using relative velocity helps us understand this interaction clearly. Here, the slab's velocity is detailed by how its motion compares to yours, ultimately showing different perspectives of movement.
Momentum
Momentum is a fundamental concept that quantifies the motion of an object, defined as the product of its mass and velocity. In a closed system, the total momentum remains constant unless acted on by external forces.
In our given example, both your movement and the slab's reaction uphold the conservation of momentum. Initially at rest, the system's momentum is zero. As you walk forward, generating a momentum of \( m \cdot v \), the slab counters this with \( 5m \cdot (-u) \), where \( u \) represents the slab's velocity.
Understanding momentum helps explain why physical systems behave predictably, reinforcing the idea that actions generate equal and opposite reactions.
Mass and Velocity Relationships
Exploring the relationship between mass and velocity helps us understand how different masses impact movement. Velocity is influenced heavily by an object's mass due to momentum conservation, seen in this problem.
You, with a smaller mass, move at a rate of 2.00 m/s whereas the larger slab moves at a slower pace of 0.40 m/s. This inverse relationship is evident from solving the equation \( u = \frac{v}{5} \).
Such relationships illustrate how heavier objects require more force or slower speeds to achieve the same momentum as lighter objects. Comprehending these dynamics enables solving more complex physics scenarios efficiently.

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Most popular questions from this chapter

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