Determine force on a body to pull or push, Mechanical Engineering

Determine force on a body to pull or push:

Q: A wooden block having weight of 50N rests on the horizontal plane. Determine force required which is acted at an angle of 15° to just (a) Pull it, and (b) Push it. Take the coefficient friction = 0.4 between the mating surfaces. Also comment on the result.

605_Determine force on a body to pull or push.png

Sol.: Let P1 be the force needed to just pull the block. In limiting equilibrium, forces are balanced. That gives

∑H = 0; F = P1cosθ

∑V = 0; R = W - P1sinθ

Also F = µR

µ(W - P1 sinθ) = P1cosθ

or P1 = µW / (cosθ  + µsinθ)

= 0.4 × 50 /( cos 15° + 0.4 sinl5°)

= 18.70N                                                                                  .......Ans

(b) Let P2  be the force which is required to just push the block. With reference to free body diagram

Let us write equations of equilibrium,

∑H = 0; F = P2cosθ

∑V = 0; R = W + P2Sinθ

Also F = µR

µ (W + P2sin θ ) = Pcosθ

or P2 = µW / (cosθ - µsinθ)

= 0.4 × 50 /( cos 15° - 0.4 sinl5°)

= 23.17N                                                                  .......Ans

Comments. It is easier to pull the given block than push it.

Posted Date: 10/17/2012 6:39:40 AM | Location : United States

Related Discussions:- Determine force on a body to pull or push, Assignment Help, Ask Question on Determine force on a body to pull or push, Get Answer, Expert's Help, Determine force on a body to pull or push Discussions

Write discussion on Determine force on a body to pull or push
Your posts are moderated
Related Questions
Evaluate the tension in the rope: Determine the tension in the rope. Solution KE of the free-body of flywheel is developed due to (i) work-done by tension T in the rop

Define O.R. and what are the applications in Industry ? A firm uses lathe, milling and Grinding machine to make two machine parts. The table below show the machining time requir

(a) What is the function of a clutch in an automobile? Illustrate the principle of friction clutches with the help of neat diagrams. (b) Discuss the working and construction of

Product Data Exchange Specifications (PDES) By 1984, many of these international efforts had produced enough results to be compared, and an international community was preparin

what is surging ?

Maintenance Operations: The maintenance operations cover various activities such as: (a) making good rain cuts in embankment, (b) clearing the side ditches of vegetatio

Types of Gas Welding Process Gas welding includes all those welding processes in which gas flame is used as a heat source for melting metals. It is further divided into three m

Your team has been charged with creating the pumping and piping system to supply cool water to the condenser, E-310, for the newly installed distillation column T-304 running at 12

What the necessary condition for a heat transfer process to occur?

what are the forces acting on workpiece during turning process. how workpiece should be clamp