WJEC Physics for AS Level: Revision Workbook

Q14 A reel contains copper wire with a diameter of 0.317 mm. Calculate: (a) The cross-sectional area of the wire in m 2 . Give your answer in standard form. [2] ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... (b) The volume of a 85.0 cm length of the wire. [2] ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... (c) The length of this wire that could be produced from a block of copper of mass 2.50 kg. [The density of copper is 8.96 × 10 3 kg m −3 .] [3] ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... (a) A gas at a pressure of 2.50 MPa is held by a piston in a cylinder of radius 10.0 cm. Calculate the force that the gas exerts on the piston. [2] ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... (b) A sample of gas is held in an open-ended pipe by a piston consisting of a solid disc of copper, of length 10.0 cm, as shown. The pressure, p A , of the air above the copper disc is 101 kPa. Calculate the pressure, p , of the gas. [Hint: the disc is held in position by a net upward force due to the pressure difference.] [4] (Density of copper = 8.96 × 10 3 kg m −3 ) ......................................................................................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................... Q15 10 cm p p A gas sample 16 | WJEC Physics for AS Level: Revision Workbook | Unit 1: Motion, Energy and Matter