Question regarding Newton's laws

AI Thread Summary
To solve problems using Newton's laws, particularly in the context of a mass on a frictionless incline, it's essential to apply Newton's second law to find acceleration. In the given scenario, the force acting on the mass and the incline's angle must be considered to break down the weight vector into its x and y components. Establishing a coordinate system with the x-axis parallel to the incline simplifies the analysis. The question specifically asks for the magnitude of acceleration, indicating that the second law is necessary for the solution. Properly categorizing the problem as homework or not is also emphasized to maintain forum guidelines.
r3dxP
well, my question isn't directly towards Newton's law or anythiing, but its a question on how to solve problems using Newton's law.
for example, look at this problem below..

a force of 20N acts horizontally on a mass of 10kg being pushed up a fritionless incline that makes a 30degrees angle with the horizontal. What is the magnitude of the acceleration of the mass up the incline equal to?

ok, for this problem, how would you know you solve this problem by using the equilibrium in respect to the x ? is it because only x equilibrium exists? or is it because its asking for the magnitude of the acceleration up the incline?
sorry if this question confuses you..
 
Physics news on Phys.org
You're going to need Newton's second law, not the first. The acceleration is what you are looking for. That's what the question states to find. Always start with what is given to and asked of you. I always put my coordinate system with the x-axis parallel to the incline. That way the only term that should need being broken down into components is the weight vector. It will have a component in both x and y directions. Write out your 2nd law equations for both axes.
 
This was also posted in the homework forum. Please don't double post. If this is homework it shouldn't be here. (And if it's not homework, it shouldn't be there!)
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Thread 'Beam on an inclined plane'
Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
Back
Top