Question

3A. A 100-N block on a rough 30degrees-incline is acted upon by a force P as shown causing it to accelerate at 2 m/s^2 u...


3A. A 100-N block on a rough 30degrees-incline is acted upon by a force P as shown causing it to accelerate at 2 m/s^2 up the plane. The coefficient of kinetic friction is 0.30.

(a) Draw the FBD of the block

(b) Find the magnitude of P

Transcribed: P 20° 30°

Answer

Solution:-Given thatW=100 Na=2 m/s2μk=0.3

Advanced Physics homework question answer, step 1, image 1

(a) FBD of block is shown below:

Advanced Physics homework question answer, step 2, image 1

(b) Now, applying Newton's first law in y direction; Fy=0N-W Cos30-PSin50=0N=W Cos30+PSin50            -(1)Again, applying Newton's second law in x direction; Fx=maP Cos50-fk-WSin30=Wgawhere fk=kinetic friction=μN=μ(W Cos30+PSin50)P Cos50-μ(W Cos30+PSin50)-WSin30=WgaP Cos50-0.3(100 Cos30+PSin50)-100Sin30=1009.81×2P Cos50-0.3 PSin50=1009.81×2+100Sin30+0.3×100 Cos30P=1009.81×2+100Sin30+0.3×100 Cos30Cos50-0.3 Sin50P=233.35 N

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