Mechanical advantage, acceleration, work, power

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Homework Help Overview

The discussion revolves around problems related to mechanical advantage, force, mass, and acceleration in a physics context. Participants are exploring concepts related to pulleys, lifting forces, and Newton's laws of motion.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to understand how to set up problems involving mechanical advantage and force calculations. Some participants suggest using fundamental physics formulas, such as F=ma, to find mass and discuss the relationship between force, mass, and acceleration. Others question the relevance of velocity in the context of force calculations.

Discussion Status

Participants are actively engaging with the problems, offering guidance on formulas and approaches. There is a mix of understanding and uncertainty, with some participants confirming the correctness of the formulas being discussed. Multiple interpretations of the problems are being explored, particularly regarding the application of Newton's laws.

Contextual Notes

The original poster expresses a desire for examples to better understand the material, indicating a review context with multiple problems to solve. There are hints of confusion regarding terminology and the application of concepts, such as the mass of the whale shark and the role of velocity in force calculations.

DerekP
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Basically i have no clue how to do this so I was hoping someone could help me on the formulas with some and explain/show how to set it up. Thanks :)

1. a block and tackle (a system of pulleys) with a mechanical advantage of 48 is used to life a piano 11 m to the third floor of a building. Although the pullets in the block and tackle make it easy to lift it still takes a long time because of the length of the rope. What is the length? (hint: its the input distance)

2. the whale shark is the largest of all fish and can have the pass (I believe she meant mass) of three adult elephants. Suppose that a crane is lifting a whale shark for delivery to an aquarium. The crane exerts a force of 2.5*104N to lift the shark from rest. If the shark's acceleration equals 1.25 m/s2, what is the sharks mass?

3. Suppose a meteorite collides with Earth with a force of 6.41*1012N.

A. What is the mass of the meteorite if it's impact speed is 10 km/s so that it has an acceleration of approximatley -1.00*108 m/s2

P.S. I'm not trying to take the easy way out and cheat the thing has about 50 problems so I'm just trying to get some examples because I don't understand this section of my review and I don't want to do bad on the final.
 
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DerekP said:
2. the whale shark is the largest of all fish and can have the pass (I believe she meant mass) of three adult elephants. Suppose that a crane is lifting a whale shark for delivery to an aquarium. The crane exerts a force of 2.5*104N to lift the shark from rest. If the shark's acceleration equals 1.25 m/s2, what is the sharks mass?

Use F=ma!
 
I'm going to be honest idk what that is. I'm guessing Force=Mass*Acceleration?
 
3- u may use simply the Newton'ssecond law..velocity has nothing to do with the force since acceleration is given just divide force by accelaration to get the mass
 
1- MA=(effort distance/load distance) just use the formula to claculate here load distance is 11m and MA is 48 so effort distance or length of rope is 48*11
 
DerekP said:
I'm going to be honest idk what that is. I'm guessing Force=Mass*Acceleration?

Yup!
 
So since I want mass it would be mass=force/acceleration?
 
DerekP said:
So since I want mass it would be mass=force/acceleration?

Yes.
 
ah thank you everyone
 

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