Center of Mass problem: 40kg child on a boat catching a turtle

In summary, the problem involves a 40 kg child standing at one end of a 70 kg boat that is 4 meters long. The boat is initially 3 meters from the pier. The child wants to catch a turtle on a rock at the far end of the boat and walks towards it. Neglecting friction between the boat and water, the child and boat move in such a way that the center of mass remains the same. When the child reaches the far end of the boat, he is still 3 meters from the pier. Whether or not he can catch the turtle depends on whether he can reach 1 meter in front of him.
  • #1
saskiwi4
1
0

Homework Statement


A 40 kg child stands at one end of a 70 kg boat that is 4 meters in length. The boat is initially 3 meters from the pier. The child notices a turtle on a rock near the far end of the boat and proceeds to walk to that end to catch the turtle. Neglect friction b/w the boat and water.

a. describe the subsequent motion of the sysyem (child+boat)

b. where is the child relative to the pier when he reaches far end of the boat?

c. Does he catch the turtle? (The child can reach out 1m in front of him.)


Homework Equations





The Attempt at a Solution



I can't figure out how to solve this at all. It is a practice problem for my test tomorrow and I simply do not understand how to do COM problems... All help is much appreciated!
 
Physics news on Phys.org
  • #2
vfd17l.png
That was a question on my physics assignment, either we're in the same class or this is a very common question. But anyway the centre of mass of the child+boat never changes so as the child walks forward the boat moves back so that the centre of mass stays the same.
 

1. What is the definition of center of mass?

The center of mass is the point within an object or system of objects where the mass can be considered to be concentrated. It is the average position of all the mass in the system.

2. Why is the center of mass important in the context of a boat and a child catching a turtle?

The center of mass is important because it determines the overall stability and balance of the system. In the given scenario, the child's position on the boat affects the center of mass, which can impact the boat's stability and the child's ability to catch the turtle.

3. How is the center of mass calculated?

The center of mass is calculated by taking into account the mass and position of each component in a system. For the boat and child scenario, the center of mass can be calculated using the formula: x = (m1x1 + m2x2) / (m1 + m2), where x is the position of the center of mass, m is the mass, and x1 and x2 are the positions of the boat and child, respectively.

4. How does the mass of the child affect the center of mass?

The mass of the child directly affects the center of mass. As the child's mass increases, the center of mass shifts towards the child's position. This means that the boat will become less stable and may tip over if the child's mass is too great.

5. Can the center of mass change during the scenario?

Yes, the center of mass can change during the scenario. As the child moves around on the boat or catches the turtle, their position and mass will affect the overall center of mass. Additionally, if the turtle is caught, its mass will also impact the center of mass. The center of mass will continue to change until the system reaches equilibrium.

Similar threads

Boat with Friction: CoM / Minimum Time Problem
    • Introductory Physics Homework Help
Replies
1
Views
1K
Center of Mass - Man on Boat Homework help
    • Introductory Physics Homework Help
Replies
7
Views
6K
Center of Mass and Motion of Objects: A Mechanics Exam Review Question
    • Introductory Physics Homework Help
Replies
5
Views
2K
Walking in a Boat (Center of Mass?)
    • Introductory Physics Homework Help
Replies
2
Views
6K
How Should the Rescue Boat Adjust Its Heading if the Child Swims Upstream?
    • Introductory Physics Homework Help
Replies
4
Views
4K
Center of mass and momentum in boat question
    • Introductory Physics Homework Help
Replies
8
Views
3K
How Does the Center of Mass Stay Constant When a Child Walks on a Boat?
    • Introductory Physics Homework Help
Replies
2
Views
6K
Momentum Help: Solving a Child's Physics Problem
    • Introductory Physics Homework Help
Replies
2
Views
2K
Two people on a boat(center of mass)
    • Introductory Physics Homework Help
Replies
16
Views
25K
Finding the Center of Mass of a Man-Boat System
    • Introductory Physics Homework Help
Replies
1
Views
7K

Hot Threads

Recent Insights

Back
Top