By making and testing simple balloon rockets, students acquire a basic understanding of Newton's third law of motion as it applies to rockets. Using balloons, string, straws and tape, they see how rockets are propelled by expelling gases, and test their rockets in horizontal and incline conditions. They also learn about the many types of engineers who design rockets and spacecraft.
Greek taxi drivers strike
Jul.18 - Tourists wait out delays in Greece's capital as taxi drivers block highways and the city of Piraeus to protest law making it easier to get taxi licenses. Jessica Gray reports.
Starfall's excellent interactive treatment given to the letter "H h”, with emphasis on the sound of the letter. Several examples and very clear pronunciation.
TheraCord Blood Collection Device
The Johns Hopkins Center for Bioengineering Innovation in the department for Biomedical Engineering at the Whiting School of Engineering hosts its annual Design Day to showcase student research.
What is Heat?
"In Physics, heat is not in inside an object, but heat is the transfer of energy from one object to another so when you touch an object and it feels hot, what you're feeling is the heat you're feeling the energy being transferred from that hot object to your hand." (01:09)
Stephenson didn't want to compromise PM
July 19 - Stephenson provides a further explanation to his resignation statement, saying he "didn't want to compromise the Prime Minister in any way by revealing or discussing a potential suspect." Rough Cut (no reporter narration).