**Question 1**

The system below is in equilibrium. Frictional forces can be neglected. | |

a) | Given that m_{2} = 0·2kg, calculate m_{1}. |

b) | Calculate the gravitational potential energy gained by m_{1} if m_{2} is pushed down 0·3m. |

c) | If m_{1} is removed and replaced by an object of mass 2m_{1}, calculate the acceleration of the system. |

d) | Calculate the total kinetic energy of the system after 2s of acceleration (with the mass 2m_{1} in place and assuming that v_{o} = 0). |

**Question 2**

A body rests, without slipping, on a plane which is inclined at 30° to the horizontal. | |

a) | Draw a diagram showing the forces acting on the body. |

b) | If the body has a mass of 2kg, calculate the magnitude of the force of friction acting on it. |

**Question 3**

An object of mass m = 5kg is being pulled up an inclined plane which is at 40° to the horizontal. The object is pulled at a constant speed of 0·8ms^{-1} by a force which acts parallel to the inclined plane. The coefficient of friction between the object and the plane is 0·2. | |

a) | Draw a diagram showing the forces acting on the object. |

b) | Calculate the magnitude of the force of friction acting on the object. |

c) | Calculate the gain in g.p.e. when the object has moved 0·5m (measured parallel to the slope). |

d) | Calculate the total work done in pulling the block 0·5m (measured parallel to the slope). |