Help please -- Free body diagram for a weightlifter?

Click For Summary
SUMMARY

The discussion centers on creating a free body diagram for a weightlifter standing up at constant speed while holding a barbell. The key forces involved are the gravitational force (Fg), the normal force, and the force exerted by the barbell. The participant incorrectly represented the force by the barbell as being in the same direction as the gravitational force and of lesser magnitude, leading to an inaccurate depiction of the net force, which should be zero for constant speed. Correctly identifying and representing these forces is crucial for an accurate free body diagram.

PREREQUISITES
  • Understanding of free body diagrams
  • Knowledge of Newton's laws of motion
  • Familiarity with vector representation of forces
  • Basic principles of equilibrium in physics
NEXT STEPS
  • Study the principles of free body diagrams in physics
  • Learn about Newton's second law and its application in static and dynamic scenarios
  • Explore vector addition and subtraction in force diagrams
  • Review examples of free body diagrams involving multiple forces
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators and tutors assisting with force analysis and free body diagram creation.

jujuju
Messages
1
Reaction score
0

Homework Statement



A weightlifter stands up at constant speed from a squatting position while holding a heavy barbell across his shoulders. Draw the free body diagram of the lifer using Fg, normal force, and force by barbell

Homework Equations



Fnet=0 ?

The Attempt at a Solution


I tried drawing the normal force up and the force of gravity down with equal magnitude with each other. I also placed the force by barbell the same direction as the force of gravity with less magnitude than the force of gravity of the lifter. It says it is wrong. What am I doing wrong? I am pretty sure the force by barbell vector is not correct but i do not know how to fix it
 
Physics news on Phys.org
jujuju said:
I tried drawing the normal force up and the force of gravity down with equal magnitude with each other. I also placed the force by barbell the same direction as the force of gravity with less magnitude than the force of gravity of the lifter. It says it is wrong. What am I doing wrong? I am pretty sure the force by barbell vector is not correct but i do not know how to fix it
What is the net force on the lifter, according to your diagram? Is it zero? Sounds like it is not.
 
  • Like
Likes   Reactions: berkeman and jujuju

Similar threads

Why are moments not included in free body diagrams?
  • · Replies 31 ·
2
Replies
31
Views
2K
Potential Mistake in Free-Body Diagram
  • · Replies 5 ·
Replies
5
Views
2K
Free Body Diagram of Mass-Spring System
  • · Replies 5 ·
Replies
5
Views
2K
Free body Diagram of a Plank resting on two Cylinders
  • · Replies 14 ·
Replies
14
Views
3K
Finding Radial Force from Free Body Diagram
  • · Replies 4 ·
Replies
4
Views
2K
Solving Free-Body Diagrams for Moving Nuts on Rods: Tips and Techniques
  • · Replies 9 ·
Replies
9
Views
2K
Free Body Diagram for a Piece of Gum on the Underside of a Desk
  • · Replies 6 ·
Replies
6
Views
2K
Free body diagram on a block pushed against a ceiling
  • · Replies 7 ·
Replies
7
Views
4K
Statics free body diagram (frames and machines)
  • · Replies 5 ·
Replies
5
Views
4K
Is it friction or tension acting on the person hanging on a rope?
  • · Replies 4 ·
Replies
4
Views
1K