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

Explain the principle of screw conveyer, Explain the Principle of screw con...

Explain the Principle of screw conveyer When materials are feed into the fixed chutes, due to action of gravity of materials and the friction force between material and chute t

Spot welding of different metals-stainless steel, Spot welding of different...

Spot welding of different metals-Stainless steel Stainless steel is having lower thermal conductivity compared to mild steel. Therefore, it requires less heat input. But, stain

Seismic loads for structure-mounted equipment, Q. Seismic Loads For Structu...

Q. Seismic Loads For Structure-Mounted Equipment? For equipment mounted in a structure above grade, the governing equation for seismic force is: F p = A v C c Pa c W c , wh

Group technology, comparing the different coding systems ?

comparing the different coding systems ?

Evaluate thermal efficiency of the engine, A carnot engines performs betwee...

A carnot engines performs between two reservoirs whose difference in temperature is 200 o C. If the work output of the engine is 0.5 times the heat rejected, make evaluation for th

Description of various sections and terminologies spark plug, Description a...

Description about Various Sections and Terminologies of Spark Plug Stud This is fixed to the insulator. The high-tension cord is also connected to this. Corrugations

Evaluate the stresses in the concrete and steel bars, A load of 1.9 MN is a...

A load of 1.9 MN is applied on a short concrete column 300mm x 300mm. The column is reinforced with four steel bars of 10mm diameter, one in each corner. Evaluate the stresses in t

Spot welding of different metals-low carbon steel, Spot welding of differen...

Spot welding of different metals-Low carbon steel Normally, mild steel can be spot welded from the thinnest gauges to a maximum of two pieces of 12 mm thickness. The restrictio

Bearing bronzes, Bearing Bronzes This is the copper-tin alloys along w...

Bearing Bronzes This is the copper-tin alloys along with small additions of another constitution. Beneath conditions of heavy load and conditions of severe service, bronzes ar

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