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

Assignment Help:

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.


Related Discussions:- Determine force on a body to pull or push

Frames, Introduction and conclusion on frames

Introduction and conclusion on frames

Law of Parallelogram of Forces, To finding ? in Law of parallelogarm forces...

To finding ? in Law of parallelogarm forces We take Q sina(Along Vertical Side) & Q cosa(Along Horizontal Side) I didn''t get that point Q sina & Q cosa how it derived? Can you

Theory of machines, what is coriolis component of acceleration?

what is coriolis component of acceleration?

Moment of resistance, Explain the Moment of resistance? Sol.: The two...

Explain the Moment of resistance? Sol.: The two equal and unlike parallel forces, the lines of action of which are not same, form couple. The resultant compressive force ( P

Define external broaching - types of broaching, Define External Broaching -...

Define External Broaching - Types of Broaching External broaching is employee for machining a flat surface. The broach is in the form of a small length tool mounted on a slider

control valve, How to design pressure control valve drill plug? How to sel...

How to design pressure control valve drill plug? How to select stroke and hole diameter and quantity?

Cam-basic components of engine , Cam: This is an integral part of camshaf...

Cam: This is an integral part of camshaft. A cam is designed in such a way as to open or close the valves at the correct timing and keep them open for the necessary duration.

Find out the centre of gravity of solid sphere, Find out the centre of grav...

Find out the centre of gravity of solid sphere: Find out the C. G. of a body formed by a solid sphere placed over a solid cylinder of similar radius a as illustrated in Figure

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd