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 .
Answer:
a. the core will spin faster.
Explanation:
By law of conservation of angular momentum
(mvR)i= (mvR)f
m= mass of star
v= speed of star
R= radius of star
i= initial
f= final
since, size(R) of the star is reduced by factor of 10,000 and mass remains the same, the velocity must increase by the same factor to keep the angular momentum conserved.
Hence, a. the core will spin faster.
<em>Choice-C</em> is the right one.
-- The bolt didn't react to the magnet, and just laid there. That tells you that the bolt was made of a non-magnetic material.
-- The bolt didn't float. It went straight to the bottom. That tells you that it's more dense than the fluid around it.
Answer:
This is one of the hottest summers America has ever seen and Jeremiah Warren is taking advantage of the heat wave and doing a little cooking…in his car!
It was about 98 or 99 degrees in Texas, so Jeremiah thought he’d head outside to see if it was hot enough to actually cook food. He buttered up a frying pan on his dashboard and filled it with an egg, cookie dough, a hot dog and bacon (mmm…bacon!). He set up another frying pan on the sidewalk and a few hours later he came back for a mid-day snack.
Explanation:
