Go Back   Physics Help Forum > High School and Pre-University Physics Help > Kinematics and Dynamics

Kinematics and Dynamics Kinematics and Dynamics Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old Aug 10th 2017, 05:02 AM   #1
Junior Member
 
Join Date: May 2017
Location: Sri Lanka
Posts: 15
Hammer and nail torque

Can you help me on solving this problem.

θ=30 and when F=150N nail tries to remove. The force exerts by the nail is paralleled to the hammer.

1 Find the force exert by the single point of contact?

2.Find the force exert by the hammer to the nail?
Attached Thumbnails
Hammer and nail torque-torque.gif  
osalselaka is offline   Reply With Quote
Old Aug 10th 2017, 03:59 PM   #2
Senior Member
 
Join Date: Apr 2015
Location: Somerset, England
Posts: 547
There are four forces acting on the hammer.

When the nail is about to move these forces maintain equilibrium and you can write the 3 equations of equilibrium involving these four forces and the geometry of the diagram.

Have you tried this?
studiot is online now   Reply With Quote
Old Aug 10th 2017, 08:15 PM   #3
Junior Member
 
Join Date: May 2017
Location: Sri Lanka
Posts: 15
Originally Posted by studiot View Post
There are four forces acting on the hammer.

When the nail is about to move these forces maintain equilibrium and you can write the 3 equations of equilibrium involving these four forces and the geometry of the diagram.

Have you tried this?
I tried to solve the problem.

I took the force which is exert by the nail on the hammer as Fn ,

The perpendicular distance to the nail force (Fn) from the single point of contact-5sin60

when we take the torque on the single point of contact,

150*30=5sin60*Fn
150*30=5*√3/2*Fn
Fn=1800/√3

Am I correct?
osalselaka is offline   Reply With Quote
Old Aug 11th 2017, 03:17 AM   #4
Senior Member
 
Join Date: Apr 2015
Location: Somerset, England
Posts: 547
Originally Posted by osalselaka View Post
I tried to solve the problem.

I took the force which is exert by the nail on the hammer as Fn ,

The perpendicular distance to the nail force (Fn) from the single point of contact-5sin60

when we take the torque on the single point of contact,

150*30=5sin60*Fn
150*30=5*√3/2*Fn
Fn=1800/√3

Am I correct?
Are you?

You didn't comment on my suggestion.

Consider horizontal force equilibrium.

Does F = the horizontal component of Fn,

Which gives a different equation from your torque equation.

There must be one more force acting that you have not considered, can you tell me what it is?
studiot is online now   Reply With Quote
Old Aug 12th 2017, 03:29 AM   #5
Junior Member
 
Join Date: May 2017
Location: Sri Lanka
Posts: 15
Yes , According to the horizontal equilibrium Fnsin30=F.

Therefore Fnsin30=150
Fn=150*2=300N

Is the forth force you saying is gravity force of the hammer?
osalselaka is offline   Reply With Quote
Old Aug 13th 2017, 03:23 PM   #6
Senior Member
 
Join Date: Apr 2015
Location: Somerset, England
Posts: 547
Here is a force diagram using only three forces acting on the hammer.

R is the (angled downwards) reaction of the nailhead on the claw.

V is the vertical reaction at C, the point of contact of the hammerhead on the table.
It is vertical because the table is shown horizontal.

Simple horizontal equilibrium calculation yields R = 300kN

But using the geometry of triangle ABC and calculating the moment equilibrium about C we find that R works out at 1039kN

So something is wrong.

Given that I have told you that you need a fourth force, can you see what this is?
Attached Thumbnails
Hammer and nail torque-hammer1.jpg  
studiot is online now   Reply With Quote
Reply

  Physics Help Forum > High School and Pre-University Physics Help > Kinematics and Dynamics

Tags
hammer, nail, torque



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Finding time for velocity ( water hammer related) doskdan Thermodynamics and Fluid Mechanics 1 Mar 26th 2017 11:07 AM
Metal hit by hammer, pulse HelenaStage Waves and Sound 0 Mar 8th 2010 10:11 AM
Torque mermejmm Energy and Work 1 Oct 19th 2009 09:48 PM
Torque angelica Advanced Mechanics 2 Jul 24th 2009 08:57 AM
hammer throw deformation nejikun Kinematics and Dynamics 2 May 3rd 2009 09:52 AM


Facebook Twitter Google+ RSS Feed