Answer: Option (a) is the correct answer.
Explanation:
AC current stands for alternating current. In an alternating current there is periodically reverse movement of current.
This means electrons move in one direction for a certain time and then they reverse their movement for the same time period and it continues in the back and forth position.
Thus, we can conclude that the statement electrons move back and forth is true regarding AC current.
Seconds squared is the time unit of acceleration. It represents the change in distance units per second per second. For example, 3 m/sec² means a distance covering 3 meters in the first second, then 9 meters in the 2nd second, and 37 meters in the third second. (3^1, 3^2, 3^3).
Acceleration is part of Newton's 2nd law: force = mass x acceleration. Units of work: joule = kg·m²/s², and power: watts = kg·m²/s³ all contain accelerations.
Answer:
Water has the ability to release a large amount of energy during the freezing process. All of this energy is released into the air, resulting in a greater movement of air particles that will increase the air temperature. This heat will prevent air temperatures from drastically falling below 0ºC.
Explanation:
The latent heat of water occurs when the water is changing its physical state. In other words, when substances are changing their physical state, the amount of heat calculated for this change is called latent heat, and as we have already said, this heat is not related to the heat exchanges between two systems, but the change of state. physicist.
When water is changing from its liquid state to a solid state, we call latent heat latent heat from fusion (this is because fusion is the name we give to when liquid water is turning to ice). In the process of freezing the page, latent heat releases a large amount of energy into the air near the water. This energy agitates the air molecules, generating heat and preventing the air from reaching temperatures below 0ºC.
Answer:
<em> B.0</em>
Explanation:
Change in momentum: This is defined as the product of mass and change in velocity of a body. or it can be defined as the product of force and time of a body. The fundamental unit of change in momentum is kg.m/s
Change in momentum = M(V-U)......................... Equation 1
where M = mass of the ball, V = final velocity of the ball, U = initial velocity of the ball.
Let: M = m kg and V = U = v m/s
Substituting these values into equation 1
Change in momentum = m(v-v)
Change in momentum = m(0)
Change in momentum = 0 kg.m/s
<em>Therefore the momentum of the ball has not changed.</em>
<em>The right option is B.0</em>
The deceleration experienced by the gymnast is the 9 times of the acceleration due to gravity.
Now from Newton`s first law, the net force on gymnast,
Here, W is the weight of the gymnast and a is the acceleration experienced by the gymnast (
acceleration due to gravity)
Therefore,
OR 
Given 
and
Substituting these values in above formula and calculate the force exerted by the gymnast,
