Answer:
Frequency, 
Explanation:
We have,
Speed of radio waves is 
Wavelength of radio waves is 
It is required to find the frequency of the radio waves. The speed of a wave is given by :

So, the frequency of the radio wave is
.
Answer: D <u>(chemical</u> -> <u>heat</u> -> <u>mechanical</u>)
In automobile engines the petrol/diesel fuel enter in to the engine cylinder, due to spark at the end of the compression, fuel burnt increase the temperature and pressure, develops heat <em>(chemical energy -> heat energy). </em><em>This heat energy acts on a piston develops the work on the crankshaft </em><em>( Heat energy -> Mechanical energy)</em><em>. </em>
Distance = speed X time
In this example, the speed of the airplane = 840km. The time (that the question is asking)is how far can it travel in 1 hour.
So just plug in your numbers.
Distance = 840km X 1 hour = 840km/hour or 840km for short.
Answer:
D. Wind turbines take up a lot of space.
Explanation:
In wind turbines the kinetic energy received by the air molecules is converted into electrical energy by the use of turbines
So here in order to get more kinetic energy from air we need more crossectional area of the wind mill to interact with the air
So here we need the large size of turbines
so this is the main disadvantage of the wind turbines because it needs large area to install the whole setup also the efficiency of this turbine is small so it needs large number of wind mills to setup good output power
so correct answer will be
D. Wind turbines take up a lot of space.
Answer:
Explanation:
There are three basic ways to increase the likelihood of safely dropping an egg:
Slow down the descent speed.
Parachutes are an obvious method for slowing the decent speed, as long as the design includes a way to keep the parachute open.
Cushion the egg so that something other than the egg itself absorbs the impact of landing.
The largest end of the egg has an area of air trapped between the egg's two membranes. This air space forms when the contents of the egg cool and contract after the egg is laid. It accounts for the crater you often see at the end of a hard-cooked egg. Upon impact the heavier spherical yolk continues moving towards the ground. The compression of the airspace acts like an air bag for the eggs' valuable contents. Building an artificial cushioning device will also help absorb the impact of landing.
The largest end of the egg has an area of air trapped between the egg's two membranes. This air space forms when the contents of the egg cool and contract after the egg is laid. It accounts for the crater you often see at the end of a hard-cooked egg. Upon impact the heavier spherical yolk continues moving towards the ground. The compression of the airspace acts like an air bag for the eggs' valuable contents. Building an artificial cushioning device will also help absorb the impact of landing.
Orient the egg so that it lands on the strongest part of the shell.
The arch structure at either end of the egg is stronger than its sides. Pressure is distributed down (or up) the arches so that less pressure acts on any one point. Orienting the arch downwards will increase the egg's survival.
Hope this helps you