Copy and complete the table, determining the missing amplitudes and intensities, in terms of A 0 and I0. However, some energy is lost to the surroundings and does not contribute to the vaporisation of the water. d Show that the component of the skier’s weight at right angles to the slope is equal to the contact force. b Calculate the work done in transferring a single electron from the upper plate to the lower plate. c In an attempt to determine g using projectile motion, a student fires a metal ball with an initial velocity of 12.

b Which of these two thermometers generates a voltage that depends on the temperature difference between two points? Using the correct terms to explain stationary waves It is important to be able to use terms such as amplitude and phase correctly and to make comparisons. ideal gas: a gas that behaves according to the equation pV = nRT mole: the amount of a substance that contains the same number of particles as there are in 0. Electrical power and energy This exercise provides practice in using several electrical formulae for power. c Sketch a graph to show how you would expect the mass’s acceleration to vary with time, starting with the mass in its position of maximum negative displacement.a State how you can obtain a stationary wave on the string and how you would recognise the positions of nodes and antinodes. State the difference between the direction of electron flow in a circuit and the direction of the conventional current. d Show the resultant displacement if the original and the wave in part c pass through the same point. c Draw the diagram and resultant again, with each wave having moved a further quarter of a wavelength in opposite directions.

Use the graph to deduce: a the displacement of the runner after 75 s b the time taken by the runner to complete the first 200 m of the race c the runner’s velocity. Resistivity and resistance: harder problems This exercise gives you practice in some harder examples where you have to use R = ρl . Calculate the six possible values for the total resistance of the circuit and describe each combination of the resistors. b Describe how this number changes when the material is heated so that it changes from a solid to a liquid and then to a gas.

d Suggest how the experiment can be used to determine how the speed of the wave on the string depends on the tension in the string. a Explain how you can tell from the pattern of the field lines that this is a uniform electric field. in each of the three closed loops: Choose a direction to follow around a loop, in the direction of the current. You may need to find the value of a trigonometric function (such as sine or cosine) of an angle whose value is given in radians. radio waves ultrasound waves microwaves ultra-violet waves waves on a rope c Describe how to use a long spring to produce a longitudinal wave that travels along the spring.