“The mechanical energy is conserved" in the given system is true out of all given options.
Answer: Option 2
<u>Explanation:
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According to law of conservation of energy, the energy will neither be created nor be destroyed, irrespective of the type of energy. As in the present case, the ball is bowled and it is travelling to ground, so the mechanical energy is working in this case. Thus the mechanical energy will be conserved. Even it can be shown as follows.
As the 2 kg ball is travelling with a speed of 7 m/s, the kinetic energy exhibited by the ball while falling to ground will be
Thus, applying given values, we get,
Similarly, as the ball is 2.5 m above ground, the potential energy will also be exhibited by the ball at that position. So the potential energy will be
Thus,
Thus as the magnitude of kinetic energy is equal to the magnitude of potential energy exhibited by the ball with varying direction, the net energy will be zero. This is because the kinetic energy will be acting in opposite direction to the potential energy exhibited by the ball. Hence as the net energy is zero, the mechanical energy is conserved.
I think the answer is b Behaviors of the electrons help cause both the shininess and the conductivity of metals
Answer:
Explanation:
From the question we are told that
The electric filed is
Generally according to Gauss law
=>
Given that the electric field is pointing downward , the equation become
Here is the excess charge on the surface of the earth
is the surface area of the of the earth which is mathematically represented as
Where r is the radius of the earth which has a value
substituting values
So
Here s the permitivity of free space with value
substituting values
The answer to this question is "Greater than". As per the OSHA or Organizational Health and Health Organization, a noise level of 95 DB or decibels is greater than the lowest level at which hearing protection is required in 85 decibels and the person's exposure should be limited only to six hours or less than of it.