question_answer

The work done in pulling up a block of wood weighing 2 kN for a length of 10m on a smooth plane inclined at an angle of \[15{}^\circ \] with the horizontal is [AFMC 1999; Pb PMT 2003]

A)             4.36 kJ

B)               5.17 Kj

C)             8.91 kJ

D)               9.82 kJ

Correct Answer: B

Solution :

                \[W=mg\sin \theta \times s\]                         \[=2\times {{10}^{3}}\times \sin 15{}^\circ \times 10\]             \[=5.17\,kJ\]