3. The tile on a roof becomes loose and slides from rest down the roof. The roof is modelled as a plane surface inclined at \(30 ^ { \circ }\) to the horizontal. The coefficient of friction between the tile and the roof is 0.4 . The tile is modelled as a particle of mass \(m \mathrm {~kg}\).

1. Find the acceleration of the tile as it slides down the roof. The tile moves a distance 3 m before reaching the edge of the roof.
2. Find the speed of the tile as it reaches the edge of the roof.
3. Write down the answer to part (a) if the tile had mass \(2 m \mathrm {~kg}\).