Answer:
It is impossible to create a perpetual motion machine because some of the energy will always be lost in the conversion and therefore it will eventually stop.
Correct Answer : Option B
Explanation:
The perpetual motion machine is impossible machine as it is hypothetical working machine which would be in motion for an indefinite time in continuity of the motion. The continuity of motion for an indefinite time would mean that the working principle of the machine would never allow the dissipation of energy from the machine and all the machine would ultimately reserve all the energy and be converting it into forms without any loss.
This working principle is violation of first and second laws of thermodynamics and hence a machine will eventually lose some of its energy in every conversion of the working cycle and hence there will be a time where the machine would be stopped, and hence a perpetual motion machine cannot be made.
Answer:
Time taken for car to stop = 0.89 seconds (Approx.)
Explanation:
Given:
Mass of car = 1100 kg
Speed of car = 15 m/s
Impact force = 185,000 N
Find:
Time taken for car to stop
Computation:
Change in momentum of car = M(v) - M(u)
Change in momentum of car = 1100(0) - 1100(15)
Change in momentum of car = -16,500
Time taken for car to stop = I Change in momentum of car I / Impact force
Time taken for car to stop = I-16,500I / 185,000
Time taken for car to stop = 0.89 seconds (Approx.)
Answer : The frequency decreases by a factor of 2.
Explanation :
Given that the wave travels at a constant speed. The speed of the wave is given as :

Where
υ is the frequency of the wave
and λ is the wavelength of the wave.
In this case, the speed is constant. So, the relation between the frequency and the wavelength is inverse.

If the wavelength increases by a factor of 2, its frequency will decrease by a factor of 2.
Hence, the correct option is (A) " The frequency decreases by a factor of 2 ".
all the allials must be aligned in the same direction
magnets are affected by heat, drops, and improper storage