Two trains set off at the same time from each end of a single
straight railway line. A very fast bee starts off in front of the
first train and flies continuously back and forth between the two
trains. How far does Sidney fly before he is squashed between the
Water freezes at 0°Celsius (32°Fahrenheit) and boils at
100°C (212°Fahrenheit). Is there a temperature at which
Celsius and Fahrenheit readings are the same?
Can you visualise whether these nets fold up into 3D shapes? Watch the videos each time to see if you were correct.
A wildcat will eat 3 birds every day. These three birds will eat 10 caterpillars each, every day, totaling 30 caterpillars. The 30 caterpillars will eat one small bush together every day.
a. The area that these animals live in currently has 500 small bushes: calculate the number of the other animals.
b. As you go up the food chain, the amount of energy available to the following predator decreases. For this food chain, the amount of energy available decreases by 25% for every level in the chain.
Calculate how much more energy the wildcat could obtain from becoming a vegetarian and eating the bush rather than from eating birds.
c. One year, a bacteria kills 5000 caterpillars. What effect will this have on the food chain?
d. What would happen to the cat, bird and caterpillar populations if the cats decided to become vegetarians and eat bushes to keep alive instead of starving?