Who invented the first practical helicopter and when?
Prof. Henrich Focke, a German inventor, devised the first practical helicopter called the Focke-Wulf Fw 16, which was successfully flown...
Speed
Speed of a falling raindrop
A raindrop falls on the earth with varying speeds depending on its size and weight. The gravity acts on the...
What is the journey time to our nearest galaxy?
Andromeda, the galaxy closest to the Milky Way, is about 2.5 million light years away. To travel in space, we need...
