1 A block \(B\) of mass 2.7 kg is pulled at constant speed along a straight line on a rough horizontal floor. The pulling force has magnitude 25 N and acts at an angle of \(\theta\) above the horizontal. The normal component of the contact force acting on \(B\) has magnitude 20 N .

1. Show that \(\sin \theta = 0.28\).
2. Find the work done by the pulling force in moving the block a distance of 5 m .