Chapter 2 – Working Scientifically
Consider the following statements and click to reveal the answer.
1. What is the difference between a prediction and a hypothesis?
Answer:
A hypothesis is a proposed explanation based on limited evidence while a prediction is a forecast of what will happen under certain conditions.
2. If you wanted to investigate the effects of exercise on the human body what skills would you need to be able to use?
Answer:
Depending on what you decided to focus on, you would need to be able to measure either heart rate, pulse rate, breathing rate or temperature and would therefore need to be able to count and use equipment such as clinical or digital thermometers. You would also need to be able to record your measurements in a table and then use a line graph to report the results.
3. What units would you use for measuring the following? (You may need to refer to other chapters to help you.)
- Weight
- Mass
- Temperature
- Rate of flow of electrical current
- Force
- Sound
- Energy
Answer:
Weight should be measured in newtons as it is a measurement of the force of gravity on mass; however, we tend to use grammes/kilogrammes as gravity changes little on Earth. Mass is measured in grammes/kilogrammes, temperature in degrees Celsius (or Kelvin scale), flow of current in amperes (amps), force in newtons, sound in decibels, energy in joules.
