Question

1. if you were to walk barefoot on the sidewalk and burn your feet on a hot summer day, then which two types of heat transfer would cause this? a) conduction, convection b) radiation, conduction c) convection, radiation d) none of the above 8. which of the waves above has the lowest frequency?______ 9. which one has the highest frequency?______ 10. what happens to the particles of a liquid when heat is removed and it cools off? a) the particles move slower b) the particles move faster c) the motion of the particles stays the same d) none of the above 11. why are radio waves used to study stars in our universe that are very far away? a) because radio waves have very short wave lengths b) because radio waves have very long wave lengths c) because radio waves have the highest frequency d) none of the above

Explanation:

Step1: Analyze heat - transfer in burning feet

The sidewalk gets heated by the sun through radiation. When you walk on it, heat is transferred from the hot sidewalk to your feet by conduction. So radiation and conduction are involved.

Step2: Analyze wave - frequency relationship

Frequency is the number of waves passing a point in a given time. The wave with the fewest number of cycles in a given time has the lowest frequency. Wave 3 has the lowest frequency as it has the fewest peaks and troughs in the given space.

Step3: Identify highest - frequency wave

The wave with the most number of cycles in a given time has the highest frequency. Wave 4 has the highest frequency as it has the most peaks and troughs in the given space.

Step4: Understand particle motion in cooling liquid

When heat is removed from a liquid and it cools off, the kinetic energy of the particles decreases. As a result, the particles move slower.

Step5: Know the property of radio - waves for studying stars

Radio waves have very long wavelengths. They can travel long distances through space without being easily absorbed or scattered, which makes them useful for studying distant stars.

Answer:

1. B. Radiation, conduction
2. 3
3. 4
4. A. The particles move slower
5. B. Because radio waves have very long wave lengths