Earths moon is said to be formed way back when the earth was still a molten ball of lava. Something huge crashed into it, causing a piece to fly off. Due to earths gravity, the piece cooled and began orbiting us.
Answer:
can you tell me about this property
Hmm...
dam power plant (not sure if this is considered renewable): benefits: as it creates a tourist spot bringing more money and provides electricity.
disadvantages: restricts flow of water to farms, costs millions to build.
solar power plant: benefits: sunlight just keeps coming, produces a lot of electricity for maybe half the cost.
disadvantages: takes a large crew to maintain, mostly needs to be in an open area.
Wind farm: benefits: wind we don't have to worry about much, just blows through and turns the turbines, and can produce electricity almost 24/7.
disadvantages: unsightly, needs open space and costs a lot to build
Take your pick!
Answer:
Explanation:
frequency of whistle = 1.85 x 10² = 185 Hz
frequency of beat heard = 8 beat /s . No of beat produced is equal to difference of frequencies of two sound source . Here difference is created due to Doppler effect . One of the train is moving so it will have apparent frequency which is different one from its original frequency .
When the moving train is approaching the observer , its frequency will be higher . As beat is heard at the rate of 8 beats / s , apparent frequency of approaching train will be 185 + 8 = 193 Hz .
Applying Doppler's formula of apparent frequency ,
193 = 185 x V / ( V - v ) , where V is velocity of sound and v is velocity of train .
193 V - 193 v = 185 V
193 v = 8 V
v = 8 x V / 193
= 8 x 343 / 193
= 14.21 m /s
Second possibility is that apparent velocity is less ie 185 - 8 = 177 Hz
In that case moving train will be moving away from observer . If its velocity be v
177 = 185 x V / ( V + v )
177 V + 177 v = 185 V
v = 8 x 343 / 177
= 15.50 m /s .
I believe it’s (D. Any object)
