Energy stores and transfersIB MYP Physics: Subtopic test

1. 1
   A student in Mumbai rides a bicycle to the top of a hill, then freewheels down it without pedalling before braking to a stop at the bottom.

   (a)

   Which energy store of the bicycle and rider has increased by the time the student reaches the top of the hill?

   [1 mark]

   • AKinetic
   • BElastic
   • CGravitational potential
   • DMagnetic

   (b)

   When the student brakes to a stop at the bottom of the hill, the kinetic energy is mostly transferred to which store?

   [1 mark]

   • AThe thermal store of the brakes and surroundings
   • BThe gravitational potential store of the bicycle
   • CThe chemical store of the rider
   • DThe elastic store of the tyres

   (c)

   Describe the energy changes as the student freewheels down the hill.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A hand torch contains a battery that lights a small lamp. After a few minutes the casing of the lamp feels warm.

   (a)

   In which store is the energy held before the torch is switched on?

   [1 mark]

   • AElastic
   • BChemical
   • CNuclear
   • DKinetic

   (b)

   How is energy transferred from the battery to the lamp?

   [1 mark]

   • ABy mechanical work
   • BBy heating
   • CBy radiation
   • DBy electrical work

   (c)

   Write an energy chain for the torch, naming the stores and the transfers.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A student drops a tennis ball from heights of 0.50, 1.00, 1.50 and 2.00 m onto a hard floor and measures the height of the first bounce each time. The bounce heights are 0.32, 0.64, 0.95 and 1.30 m.

   (a)

   Describe the trend in the results and calculate the bounce height as a percentage of the drop height for the 1.00 m drop.

   [3 marks]

   (b)

   Explain where the missing energy goes and suggest one weakness in the way the bounce height was measured.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A country in East Africa plans to build a large hydroelectric power station. Water stored behind a high dam falls through pipes and turns turbines that drive generators connected to the national grid. Building the dam will flood a river valley where thousands of people live.

   (a)

   Describe the energy chain from the water stored behind the dam to a lamp in a house, naming the stores and the transfers.

   [6 marks]

   (b)

   Discuss and evaluate whether the government should build the hydroelectric power station.

   [6 marks]

   Total for question 4: 12 marks

End of questions