Solving Forces with Pulleys: 420N & 190N Blocks

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Homework Help Overview

The problem involves two blocks connected by a pulley system, where one block is on a horizontal surface and the other is hanging. The weights of the blocks are given as 420 N for the block on the surface and 190 N for the hanging block. The task is to determine the acceleration and tension in the system while ignoring friction and assuming the pulley is massless.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • The original poster attempts to apply free body diagrams and equations of motion to find the acceleration and tension but expresses difficulty in arriving at a solution. Some participants question the approach of combining horizontal and vertical forces in the equations.

Discussion Status

Participants are exploring the problem with some guidance offered regarding the separation of horizontal and vertical forces. There is an acknowledgment of the original poster's struggle with the calculations, but no consensus or resolution has been reached yet.

Contextual Notes

The discussion includes the assumption of a massless pulley and the neglect of friction, which may influence the analysis of forces in the system.

rwofford
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so i have this problem with a block sitting on a horizontal surface and this block(m1) has the weight of 420 N. This block is connected by a string to a pulley and then connects to another block(m2) that is hanging from the pulley. The weight of the hanging block is 190 N. Ignore all frictional effects, and assume the pulley to be massless. I have to find the acceleration adn tension.

For this problem i know the free body diagrams..and i also know that the tension asn acceleration will be the same for both blocks. I have tried solving using the net forces but can't come up with an answer...

I have used:

sumF(m1)=Fn+Ft-Fg
sumF=ma
so: Fn+Ft-Fg=ma

sumF(m2)=Ft
sumF=ma
so: Ft=ma

but when i try to solve i am not getting an answer...please help!
 
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someone please help!
 
...hello?
 
rwofford said:
I have used:

sumF(m1)=Fn+Ft-Fg
sumF=ma
so: Fn+Ft-Fg=ma

sumF(m2)=Ft
sumF=ma
so: Ft=ma

but when i try to solve i am not getting an answer...please help!
Realize that you can't just add horizontal and vertical forces (like Fn and Ft on m1). Treat horizontal and vertical components separately.

m1 accelerates horizontally, so analyze the horizontal forces acting on m1. Similarly, m2 accelerates vertically, so analyze the vertical forces acting on m2.
 

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