Question

A block of mass 10 kg is pushed up on a smooth
plane of inclination 30°, so that it has acceleration 2
The applied force is
(1) 50 N
(2) 60 N
(3) 70 N
(4) 80 N​

Answer 1

Answer:

Applied force is option (3) 70 N

Explanation:

$\blacksquare$ Mass = m = 10 kg

$\blacksquare$ Acceleration = a = 2 m/s²

$\blacksquare$ Acceleration due to gravity = g = 10 m/s²

$\blacksquare$ Angle of inclination = X = 30°

$\blacksquare$ From the FBD or Free Body Diagram of the block we get,

the applied force along with acceleration produced is balanced by mg sinX

or

F = mgsinX + ma

Substituting the values of m, a, g and sinX

F = 10*10*sin30 + 10*2

F = 100*1/2 + 20

F = 50 + 20

F = 70 N

$\blacksquare$ The adjoining figure gives the FBD of the block