# Jesus Christ

## Jesus Christ

PHP1/JvW
Here is a collection of revision questions, focusing on understanding the main points of the course. It is also a good idea to practice doing the homework/exam questions and the examples in the course material. If you have questions, you can ask them in Wilma (I may post my answer to the whole group).
1. Give examples of a heat transfers by a) conduction, b) convection, c) radiation, d) a combination of two of these.
2. Give examples of substances that are good a) conductors b) emitters of radiation
3. What energy transfers are involved when a) a battery-driven flashlight shines, b) Ida rides a bike, c) a petroil-powered car moves forward. Draw a Sankey-diagram in each case.
4. A television set consumes 10 W (ten joules of energy per second). In a minute it produces 400 J of heat. What is its efficiency?
5. Name five different types of electromagnetic radiation. For each of these, give one example of its use.
6. Light travels at 300 000 km per second. What is the frequency of light when its wavelength is 500 nm?
7. Name three different kinds of radioactive decay and explain in what different ways they present a danger to humans.
8. A sample of a radioactive substance is locked into a safe. After 60 hours 25 % of the atoms remain. What is the half-life of the substance?
9. Explain the difference between a) speed and velocity b) mass and weight.
10. Igor starts from home on his bike, rides at full speed to his friend’s house (along a straight road), stays there for a while, and then rides slowly back home. For this scenario, draw a) a distance-time graph, and b) a velocity-time graph.
11. Explain in what way (and why) the terminal velocities of a falling feather is different from that of a falling stone.
12. The density of a special kind of wood is 1300 kg m-3. Will a block of this wood float or sink when put in a water bath? Why?
13. The Bismuth isotope with 83 protons and 130 neutrons can undergo both alpha and beta decay. How...