Mumbai University > FE > Sem 1 > Engineering Mechanics

Marks : 08

Years : MAY 2015

There are two possibilities. One is that block A moves over block B and the other is that both blocks move together over the ground.

Case 1 : Let block A move over block B

$∴Σ F_x (→ +ve)=0 \\ ∴P\cos 30-0.3 N_(1 )=0…………(I) \\ ∴Σ F_y (↑ +ve)=0 \\ ∴P \sin30+ N_(1 )-100=0…………(II) $

Solving equations (I) and (II) simultaneously,

$P = 29.53 N ,N_(1 )=85.24N $

Case 2: Let, both blocks move together over ground

$∴Σ F_x (→ +ve)=0 \\ ∴P \cos30-0.1 N_(2 )=0…………(I) \\ ∴Σ F_y (↑ +ve)=0 \\ ∴P \sin30+ N_2=250…………(II) $

Solving equations (I) and (II) simultaneously,

$P = 27.29 N$

Minimum value of P = 27.29N in which case both blocks will move together over the ground.