Does force normal change when you push an object at an angle?

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Homework Help Overview

The discussion revolves around the forces acting on a lawn mower when a force is applied at an angle. The original poster attempts to calculate the gravitational force and the normal force while considering the effects of an applied force at 30° below the horizontal.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between the normal force and the applied force, particularly how the vertical component of the applied force interacts with the gravitational force. Questions arise regarding the nature of gravitational force and whether it changes with the application of an external force.

Discussion Status

Some participants provide affirmations regarding the calculations of forces, while others raise questions about the fundamental nature of gravitational force and its independence from applied forces. The discussion appears to be exploring different interpretations of how forces interact without reaching a definitive consensus.

Contextual Notes

Participants are navigating the implications of applying a force at an angle and its effects on the normal force, while also considering the established equations of motion and gravitational force. There is an underlying assumption that the laws of physics, such as Newton's laws, apply consistently in this scenario.

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Homework Statement



You exert a force of 131 N [30° below horizontal] onto a 12.6 kg lawn mower, What is the force of gravity and normal force on the lawn mower?

Homework Equations


Fg= m × g
FA (y component) = Sin30° × FA

The Attempt at a Solution


The force of gravity is equal to the force of normal,
∴ FN = m × g
= 12.6 kg × 9.8 m/s2
= 123.48 [up]​

But, the normal force gets added on by the force opposing the y component of the applied force right?

So, FA (y component)Sin30° × FA
= 65.5 N [down]​
So by Newtons 3rd law there would be a force acting up on the lawn mower of 65.5 N[up].I'm just wondering if these two forces are added to each other for the total normal force which is 123.48 N + 65.5 N = 188.98 N [up]?
 
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Yes, all correct. The vertical component of the push adds to the weight to make the normal force pressing the mower down on the ground.
 
Thanks, but I have a question. Why doesn't the force of gravity on the lawn mower increase when you apply your force on it? Aren't you essentially making the lawn mower heavier?
 
The force of gravity depends on the MASS of the mower. You probably know it is
Fg = GMm/d² where M is the mass of the Earth and m the mass of the mower.
 

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