A block of mass $1 \mathrm{~kg}$ is pushed up a surface inclined to horizontal at an angle of $60^{\circ}$ by a force of $10 \mathrm{~N}$ parallel to the inclined surface as shown in figure. When the block is pushed up by $10 \mathrm{~m}$ along inclined surface, the work done against frictional force is :

$\left[g=10 \mathrm{~m} / \mathrm{s}^2\right]$