Fechar
What are the eight different energy stores? Give an example of each.
Give the energy store that increases in each of these examples: (3 marks)
(a) when a mass is lifted through a height
(b) when a pan of water at 20ºC water is heated to 70ºC
(c) when an extra cell is added to a circuit.
A kettle has a power rating of ® W. How much energy does it use in √ seconds?
Wind turbines are designed to use the kinetic energy of moving air to turn the turbine blades. Explain why this is described as a mechanical process and, therefore, why efficiency is important. (6 marks)
Walking uphill
Al walks directly up a hill and he takes 12 minutes to get to the top. Bev walks up the same hill on a shallower path that zig zags as it goes up. She takes 15 minutes to get to the top. Explain who has exerted the greater power, and who has transferred more energy while getting to the top of the hill. Include any assumptions you make in your answer. (6 marks)
Give the three types of fields that cause objects to interact with each other without making contact.
Explain which of these is different from the other two and why.
Why are weight and normal contact force vectors. (2 marks)
Which of the following is not one of the steps for resolving a resultant force using a scale drawing?
A The angles are drawn with a protractor.
B The scale is not important.
C The vertical component can be found through measurement.
D The horizontal line is drawn to scale. (1 mark)
Draw a free-body diagram to represent a cyclist accelerating to the left along a horizontal path.
Balanced and resultant forces are an important consideration when operating a camera drone remotely. To film an aerial sequence, the camera operator flies the drone to the required height for filming and keeps it stationary by controlling the speed of the rotor blades. Explain the balanced or unbalanced forces acting on the camera drone during operation (assume breeze is negligible). (6 marks)
