Mass, Weight and the local acceleration due to gravity

Click For Summary
SUMMARY

The discussion focuses on calculating local acceleration due to gravity and understanding mass and weight relationships. The participant, with a mass of 150 lb, calculated the local acceleration of gravity as 0.963 ft/s² using the equation F=ma, which is incorrect given that standard gravity is 32.174 ft/s². The participant also calculated the weight as 4826 lbf, which is a misunderstanding since weight should be derived from the mass and the local acceleration due to gravity. Clarification on the definitions and correct application of the formulas is necessary.

PREREQUISITES
  • Understanding of Newton's Second Law (F=ma)
  • Knowledge of the difference between mass (lb) and weight (lbf)
  • Familiarity with units of acceleration (ft/s²)
  • Basic grasp of gravitational acceleration (32.174 ft/s²)
NEXT STEPS
  • Review the concept of gravitational acceleration and its standard value of 32.174 ft/s²
  • Study the distinction between mass and weight in physics
  • Practice solving problems using F=ma with correct unit conversions
  • Explore real-world applications of mass and weight in various gravitational fields
USEFUL FOR

Students studying physics, educators teaching mechanics, and anyone interested in understanding the principles of mass, weight, and gravity calculations.

Northbysouth
Messages
241
Reaction score
2

Homework Statement


A person whose mass is 150lb weighs 144.4 lbf. Determine a) the local acceleration of gravity, in ft/s2, and b) the persons mass, in lb and weight, in lbf, if g = 32.174 ft/s2


Homework Equations


F=ma


The Attempt at a Solution


A) Using F=ma I got

144.4 lbf = (150lb)a
a = 0.963 ft/s2

My answer seems kinda low. Am I missing something?

b) F=ma

mass = 150lb

F = (150lb)(32.174 ft/sec2)
F = weight = 4826 lbf

I also feel like I'm missing something here as well, especially as it asks for the mass, which is already given. Am I misreading the question or something?

Any help would be appreciated. Thanks
 
Physics news on Phys.org
Hint: if you'd been told the person weighed just a little more, 150 lbf, what would the answer have been?
 

Similar threads

Determine Force on 6ft Door Due to Water & Air Pressure
  • · Replies 7 ·
Replies
7
Views
2K
Determine if a car can pop a wheelie?
  • · Replies 15 ·
Replies
15
Views
3K
Calculate the work required to move the block
  • · Replies 28 ·
Replies
28
Views
4K
Unraveling the Mystery of Mass & Force: A 180 lb Person
  • · Replies 3 ·
Replies
3
Views
2K
Solving Pulley Type Problem: Mass, Forces & Momentum
  • · Replies 7 ·
Replies
7
Views
2K
Newton's Third Law: Acceleration of box and worker
  • · Replies 2 ·
Replies
2
Views
5K
Calculate elevator acceleration using mass
  • · Replies 9 ·
Replies
9
Views
4K
Experimental Design: Pulley and Mass Hangers
  • · Replies 30 ·
2
Replies
30
Views
4K
Find acceleration of Moving incline with a block on it
  • · Replies 11 ·
Replies
11
Views
3K
Calculate force in english units
  • · Replies 5 ·
Replies
5
Views
18K