The correct answer is A. Charged particles from the sun exite the atmosphere near the poles to create auroras.
Answer:
Torque on the rocket will be 1.11475 N -m
Explanation:
We have given that muscles generate a force of 45.5 N
So force F = 45.5 N
This force acts on the is acting on the effective lever arm of 2.45 cm
So length of the lever arm d = 2.45 cm = 0.0245 m
We have to find torque
We know that torque is given by 
So torque on the rocket will be 1.11475 N -m
Answer:
Cost of 1000 kilowatt hour = 6000 cents
Explanation:
Given that
Electricity cost is 6 cents per kilowatt hour.
And we have to found out the cost for one megawatt hour
We know that
1 kilowatt = 1000 watt
1 megawatt = = 1000000 watt
1 megawatt = 1000 kilowatt
1 megawatt hour = 1000 kilowatt hour
Given that cost of 1 kilowatt hour = 6 cents
So the cost of 1000 kilowatt hour = 6 x 1000 cents
Cost of 1000 kilowatt hour = 6000 cents
Answer:
Explanation:
velocity of sound in air at 20⁰C is 343 m /s
velocity of sound in water at 20⁰C is 1481 m /s
The wavelength of the sound is 2.86 m in the air so its frequency
= 343 / 2.86 = 119.93 .
This frequency of 119.93 will remain unchanged in water .
wavelength in water = velocity in water / frequency
= 1481 / 119.93
= 12. 35 m .
Speed of any freely falling object is always same. Provided, both are left to fall from the same height. If you perform this experiment in a perfect vacuum or near vacuum laboratory, both of them will reach ground with same velocity this is because there is no resistance to their motion. This is always true no matter where you go and perform this experiment.
It can be easily proved from conservation of mechanical energy. Why conserving energy? because there are no forces acting on the freely falling objects other than conservative force(mg).