What is the normal force exerted?

In summary, the conversation discusses a problem involving a girl pushing a lawn mower with a force of 25N at an angle of 34 degrees. The acceleration is found to be 0.86 m/s^2 and the normal force is calculated to be 221.22N. However, the solution is incorrect and the conversation suggests checking the direction of the forces.
  • #1
Laurili
1
0

Homework Statement

:[/B] A girl pushes a 24 kg lawn mower as show in the figure. (figure shows a girl pushing a manual push mower. The force is going down the handle and theta is from the ground to the mower.) Force=25N and theta=34 degrees. Ignore friction. Gravity does apply at 9.8 m/s^2



Homework Equations

:[/B] I already found the acceleration and checked it to make sure it was right. Acceleration was found to be 0.86 m/s^2


The Attempt at a Solution

:[/B] I first tried to find out if Fy was greater or less than mg by; Fy=25N times sin34 degrees which equaled 13.98N and mg=24kg times 9.80 m/s^2= 235.2N Then I set up the sum of the forces as; Fy+ Fn - mg= 0 ( 13.98N) + Fn - (235.2N)= 0 I found the normal force to be; Fn= 221.22N My problem is once i submitted this answer I was told I was wrong. Any help is appreciated, thanks :smile:
 
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  • #2
You have a sign wrong. Draw the force diagram, determine the directions of all forces and then recheck your equation.
 

1. What is the definition of normal force?

The normal force is the force exerted by a surface on an object in contact with it, perpendicular to the surface. It is also known as the contact force or support force.

2. How is the normal force calculated?

The normal force is calculated by multiplying the mass of the object by the gravitational acceleration (9.8 m/s²) and the cosine of the angle between the surface and the force.

3. What is the direction of the normal force?

The normal force always acts perpendicular to the surface, pushing the object away from the surface.

4. What are some real-life examples of normal force?

Examples of normal force include the weight of a book resting on a table, the force exerted by a floor on a person standing on it, and the tension in a rope suspending an object.

5. How does the normal force affect an object's motion?

The normal force affects an object's motion by counteracting the force of gravity and preventing it from falling through a surface. It also enables an object to be supported and have stable equilibrium on a surface.

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