Pulley and 2nd Newton law

In summary, the equation for finding the acceleration of the two objects and the tension force is m1a=T and m2a=-T+m2gsin45. The normal force applied by m2 is m2gcos45, but it is not necessary to consider unless friction or breakage is a concern. There is uncertainty about the accuracy of the equations and the role of m2gcos45.
  • #1
gen007
2
0

Homework Statement



http://img69.imageshack.us/img69/2429/phyq1.jpg [Broken]

Homework Equations


to find the acceleration of the 2 objects and the Tension Force.


The Attempt at a Solution



since only 1 pulley used, a=a1=a2, then
m1a=T (1)
m2a=-T+m2gsin45 (2)

i wonder what happen to the m2gcos 45?? and is the 2 equations right for my assumption? thanks
 
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  • #2
m2gcos45 is the normal force applied by m2, which isn't really important unless friction is considered (or unless it's so big that something breaks).
 
  • #3
but is the 2 equations right? because i am still ponder over m2a=-T+m2gsin45 or m2a=T+m2gsin45 ?? really sad my basic wasnt good...
 

1. What is a pulley?

A pulley is a simple machine that is used to lift heavy objects by redirecting the direction of the force needed to lift the object. It consists of a wheel with a groove around its circumference and a rope or belt that runs around the wheel.

2. How does a pulley work?

A pulley works by using the principle of mechanical advantage, which states that a smaller force can be used to lift a heavier object by using a larger distance. The pulley system reduces the amount of force required to lift an object by distributing the weight among multiple ropes and pulleys.

3. What is the second law of motion?

The second law of motion, also known as Newton's second law, states that the acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to its mass. In mathematical terms, it can be expressed as F = ma, where F is the net force, m is the mass, and a is the acceleration.

4. How are pulleys related to the second law of motion?

Pulleys are related to the second law of motion as they can be used to demonstrate the concept of mechanical advantage. By using a pulley system, the force needed to lift an object can be reduced, but the distance the force must act over is increased. This is in accordance with the equation F = ma, where a larger distance over which the force acts results in a smaller force needed to produce the same acceleration.

5. Can a pulley violate the second law of motion?

No, a pulley cannot violate the second law of motion. The second law of motion is a fundamental principle of physics that has been tested and proven through various experiments. A pulley system simply allows us to apply this law in a practical way to make tasks easier.

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