Energy and Work Done – Question 2
The diagram shows a wind turbine. (a) The blades of the turbine are 20 metres long. On average, 15 000 kg of air, moving at a speed of 12 m/s, hit the blades every second.
Archives
Moments – Question 2
4 (a) Figure 5 shows a girl standing on a diving board.
Static Electricity – Question 1
(a) The diagram shows a negatively charged plastic rod held close to a thin stream of water. The water is attracted towards the rod.
Forces and Motion – Question 1
(a) The diagram shows the horizontal forces acting on a swimmer.
Household Electricity – Question 1
(a) The picture shows a person using a set of electronic ‘Body Fat Scales’. When the person stands on the scales, a small, harmless, electric current passes through the person’s body. The scales then calculate the resistance of the person’s body and convert the resistance into a prediction of body fat content.
Nuclear Fission and Fusion – Question 1
(a) As part of its life cycle, a star changes from being a protostar to a main sequence star. Explain the difference between a protostar and a main sequence star.
Electrical Circuits – Question 1
The graph shows how the electric current through a 12 V filament bulb varies with the potential difference across the bulb.
Energy and Work Done – Question 1
The miners working in a salt mine use smooth wooden slides to move quickly from one level to another.
Electrical Appliances – Question 2
(a) The table gives information about some ways of reducing the energy consumption in a house.
Waves – Question 4
(a) The new Tetra communications system to be used by the police transmits digital signals using microwaves of wavelength 75 cm. The signals travel through the air at 300 000 000 m/s. (i) What is a digital signal?